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Math 3B: Lecture 1 Noah White January 9, 2017

Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

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Page 1: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Math 3B: Lecture 1

Noah White

January 9, 2017

Page 2: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Class website

There are a few places where you will find/receive informationabout Math 3B:

• The class website: www.math.ucla.edu/~noah• Email• Piazza• CCLE (not in use)

Page 3: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Instructor and TAs

Instructor Noah Whiteoffice hours MS 6304, W,F 10:30am-12pm

TA Max Zhouoffice hours TBA, TBA

Yuejiao SunTBA, TBA

Mengyuan DingTBA, TBA

Page 4: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Communication

• Mathematical questions should be asked on Piazza• Administrative questions should be directed to your TA initially• If you need to email me include math3b-w17 in the subject

Page 5: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Textbook

S. J. Schreiber, Calculus for the Life Sciences, Wiley

Page 6: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Problem sets, homework, and quizzes

Problem setsAssigned every week. Long list of problems. Not graded, butrecommended!

HomeworkDue every second week. A small number of questions drawn fromthe problem sets. There will be 4.

QuizzesAdministered every other week in discussion session. There will be6.

Page 7: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Problem sets, homework, and quizzes

Problem setsAssigned every week. Long list of problems. Not graded, butrecommended!

HomeworkDue every second week. A small number of questions drawn fromthe problem sets. There will be 4.

QuizzesAdministered every other week in discussion session. There will be6.

Page 8: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Problem sets, homework, and quizzes

Problem setsAssigned every week. Long list of problems. Not graded, butrecommended!

HomeworkDue every second week. A small number of questions drawn fromthe problem sets. There will be 4.

QuizzesAdministered every other week in discussion session. There will be6.

Page 9: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Homework; collection and collaboration

• Homework will be collected at the start of the lecture on thedues date.

• Late homework will not be accepted.• You may collaborate in small groups if:• you aknowledge your collaborators,• write up your own solutions, in your own words.

Page 10: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Homework; collection and collaboration

• Homework will be collected at the start of the lecture on thedues date.

• Late homework will not be accepted.

• You may collaborate in small groups if:• you aknowledge your collaborators,• write up your own solutions, in your own words.

Page 11: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Homework; collection and collaboration

• Homework will be collected at the start of the lecture on thedues date.

• Late homework will not be accepted.• You may collaborate in small groups if:

• you aknowledge your collaborators,• write up your own solutions, in your own words.

Page 12: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Homework; collection and collaboration

• Homework will be collected at the start of the lecture on thedues date.

• Late homework will not be accepted.• You may collaborate in small groups if:• you aknowledge your collaborators,

• write up your own solutions, in your own words.

Page 13: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Homework; collection and collaboration

• Homework will be collected at the start of the lecture on thedues date.

• Late homework will not be accepted.• You may collaborate in small groups if:• you aknowledge your collaborators,• write up your own solutions, in your own words.

Page 14: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Exams

There will be two midterms and a final exam

• Midterm 1 8-8:50am Monday, 30 January, 2017

• Midterm 2 8-8:50am Monday, 27 February, 2017• Final 8-11am Monday, 20 March, 2017

Cheatsheets and calculatorsYou will be allowed a small cheatsheet in each exam. Must beself-written and one side, half a letter size piece of paper. You arealso allowed to use non-programmable, non-graphing calculators.

Page 15: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Exams

There will be two midterms and a final exam

• Midterm 1 8-8:50am Monday, 30 January, 2017• Midterm 2 8-8:50am Monday, 27 February, 2017

• Final 8-11am Monday, 20 March, 2017

Cheatsheets and calculatorsYou will be allowed a small cheatsheet in each exam. Must beself-written and one side, half a letter size piece of paper. You arealso allowed to use non-programmable, non-graphing calculators.

Page 16: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Exams

There will be two midterms and a final exam

• Midterm 1 8-8:50am Monday, 30 January, 2017• Midterm 2 8-8:50am Monday, 27 February, 2017• Final 8-11am Monday, 20 March, 2017

Cheatsheets and calculatorsYou will be allowed a small cheatsheet in each exam. Must beself-written and one side, half a letter size piece of paper. You arealso allowed to use non-programmable, non-graphing calculators.

Page 17: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Exams

There will be two midterms and a final exam

• Midterm 1 8-8:50am Monday, 30 January, 2017• Midterm 2 8-8:50am Monday, 27 February, 2017• Final 8-11am Monday, 20 March, 2017

Cheatsheets and calculatorsYou will be allowed a small cheatsheet in each exam. Must beself-written and one side, half a letter size piece of paper. You arealso allowed to use non-programmable, non-graphing calculators.

Page 18: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Grading

Your final grade will be calculated using the maximum of thefollowing two grading schemes.

10% (best 8 quizzes/hw) + 40% (midterms) + 50% (final)or

10% (best 8 quizzes/hw) + 30% (best midterm) + 60% (final)

Page 19: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Schedule

See website

Page 20: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Where to get help

PiazzaHere you can ask questions and answer others’ questions. Lets takea look. . .

Office hoursUse them wisely! Prepare and seek information first. If you learnsomething, post it to Piazza!

Student Math Center (SMC)Location: MS 3974, times: M-R 9am-3pm.The SMC offers free, individual and group tutoring for all lowerdivision math courses. This service is available on a walk-in basis;no appointment is necessary. Students may ask any of the TAs inattendance for assistance with math problems.

Page 21: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Where to get help

PiazzaHere you can ask questions and answer others’ questions. Lets takea look. . .

Office hoursUse them wisely! Prepare and seek information first. If you learnsomething, post it to Piazza!

Student Math Center (SMC)Location: MS 3974, times: M-R 9am-3pm.The SMC offers free, individual and group tutoring for all lowerdivision math courses. This service is available on a walk-in basis;no appointment is necessary. Students may ask any of the TAs inattendance for assistance with math problems.

Page 22: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Where to get help

PiazzaHere you can ask questions and answer others’ questions. Lets takea look. . .

Office hoursUse them wisely! Prepare and seek information first. If you learnsomething, post it to Piazza!

Student Math Center (SMC)Location: MS 3974, times: M-R 9am-3pm.The SMC offers free, individual and group tutoring for all lowerdivision math courses. This service is available on a walk-in basis;no appointment is necessary. Students may ask any of the TAs inattendance for assistance with math problems.

Page 23: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

What should you know?

A nonexhaustive list:• Definitions and properties of basic functions.

• How to calculate limits.• You should have a good feel for what the derivative means.

I.e. derivative at a point = tangent slope.• You need to understand differentiation algebraically as well as

geometrically.• You should also know the definition of the derivative

ddx

f (x) = limh→0

f (x + h)− f (x)

h

Page 24: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

What should you know?

A nonexhaustive list:• Definitions and properties of basic functions.• How to calculate limits.

• You should have a good feel for what the derivative means.I.e. derivative at a point = tangent slope.

• You need to understand differentiation algebraically as well asgeometrically.

• You should also know the definition of the derivative

ddx

f (x) = limh→0

f (x + h)− f (x)

h

Page 25: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

What should you know?

A nonexhaustive list:• Definitions and properties of basic functions.• How to calculate limits.• You should have a good feel for what the derivative means.

I.e. derivative at a point = tangent slope.

• You need to understand differentiation algebraically as well asgeometrically.

• You should also know the definition of the derivative

ddx

f (x) = limh→0

f (x + h)− f (x)

h

Page 26: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

What should you know?

A nonexhaustive list:• Definitions and properties of basic functions.• How to calculate limits.• You should have a good feel for what the derivative means.

I.e. derivative at a point = tangent slope.• You need to understand differentiation algebraically as well as

geometrically.

• You should also know the definition of the derivative

ddx

f (x) = limh→0

f (x + h)− f (x)

h

Page 27: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

What should you know?

A nonexhaustive list:• Definitions and properties of basic functions.• How to calculate limits.• You should have a good feel for what the derivative means.

I.e. derivative at a point = tangent slope.• You need to understand differentiation algebraically as well as

geometrically.• You should also know the definition of the derivative

ddx

f (x) = limh→0

f (x + h)− f (x)

h

Page 28: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Differentiation

You should be able to differentiate many of the standard functionswe will see in this course. This includes:

• polynomials/power functions

ddx

(xn) = nxn−1

• exponentialsddx

(ex) = ex

• logarithmsddx

(ln x) =1x

• trig functionsddx

(sin x) = cos x

Page 29: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Differentiation

You should be able to differentiate many of the standard functionswe will see in this course. This includes:

• polynomials/power functions

ddx

(xn) = nxn−1

• exponentialsddx

(ex) = ex

• logarithmsddx

(ln x) =1x

• trig functionsddx

(sin x) = cos x

Page 30: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Differentiation

You should be able to differentiate many of the standard functionswe will see in this course. This includes:

• polynomials/power functions

ddx

(xn) = nxn−1

• exponentialsddx

(ex) = ex

• logarithmsddx

(ln x) =1x

• trig functionsddx

(sin x) = cos x

Page 31: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Differentiation

You should be able to differentiate many of the standard functionswe will see in this course. This includes:

• polynomials/power functions

ddx

(xn) = nxn−1

• exponentialsddx

(ex) = ex

• logarithmsddx

(ln x) =1x

• trig functionsddx

(sin x) = cos x

Page 32: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Product rule

The product rule lets us differential functions of the formf (x) = g(x)h(x). It says

ddx

f (x) = g ′(x)h(x) + g(x)h′(x)

ExampleLet’s differentiate the function f (x) = ex sin x .

ddx

f (x) =

(ddx

ex)sin x + ex

(ddx

sin x)

= ex sin x + ex cos x= ex(sin x + cos x)

Page 33: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Product rule

The product rule lets us differential functions of the formf (x) = g(x)h(x). It says

ddx

f (x) = g ′(x)h(x) + g(x)h′(x)

ExampleLet’s differentiate the function f (x) = ex sin x .

ddx

f (x) =

(ddx

ex)sin x + ex

(ddx

sin x)

= ex sin x + ex cos x= ex(sin x + cos x)

Page 34: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Product rule

The product rule lets us differential functions of the formf (x) = g(x)h(x). It says

ddx

f (x) = g ′(x)h(x) + g(x)h′(x)

ExampleLet’s differentiate the function f (x) = ex sin x .

ddx

f (x) =

(ddx

ex)sin x + ex

(ddx

sin x)

= ex sin x + ex cos x

= ex(sin x + cos x)

Page 35: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Product rule

The product rule lets us differential functions of the formf (x) = g(x)h(x). It says

ddx

f (x) = g ′(x)h(x) + g(x)h′(x)

ExampleLet’s differentiate the function f (x) = ex sin x .

ddx

f (x) =

(ddx

ex)sin x + ex

(ddx

sin x)

= ex sin x + ex cos x= ex(sin x + cos x)

Page 36: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

The chain rule

The chain rule is very important! It allows us to differentiatefunctions of the form f (x) = g(h(x)). It says

ddx

f (x) = h′(x)g ′(h(x))

ExampleLet’s differentiate f (x) = sin(ex). In this example

h(x) = ex and g(x) = sin x

soh′(x) = ex and g ′(x) = cos x

sof ′(x) = ex cos(ex)

Page 37: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

The chain rule

The chain rule is very important! It allows us to differentiatefunctions of the form f (x) = g(h(x)). It says

ddx

f (x) = h′(x)g ′(h(x))

ExampleLet’s differentiate f (x) = sin(ex). In this example

h(x) = ex and g(x) = sin x

soh′(x) = ex and g ′(x) = cos x

sof ′(x) = ex cos(ex)

Page 38: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

The chain rule

The chain rule is very important! It allows us to differentiatefunctions of the form f (x) = g(h(x)). It says

ddx

f (x) = h′(x)g ′(h(x))

ExampleLet’s differentiate f (x) = sin(ex). In this example

h(x) = ex and g(x) = sin x

soh′(x) = ex and g ′(x) = cos x

sof ′(x) = ex cos(ex)

Page 39: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

The chain rule

The chain rule is very important! It allows us to differentiatefunctions of the form f (x) = g(h(x)). It says

ddx

f (x) = h′(x)g ′(h(x))

ExampleLet’s differentiate f (x) = sin(ex). In this example

h(x) = ex and g(x) = sin x

soh′(x) = ex and g ′(x) = cos x

sof ′(x) = ex cos(ex)

Page 40: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

The chain rule

The chain rule is very important! It allows us to differentiatefunctions of the form f (x) = g(h(x)). It says

ddx

f (x) = h′(x)g ′(h(x))

ExampleLet’s differentiate f (x) = sin(ex). In this example

h(x) = ex and g(x) = sin x

soh′(x) = ex and g ′(x) = cos x

sof ′(x) = ex cos(ex)

Page 41: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

The quotient rule is stupid

The quotient rule says

ddx

(g(x)

h(x)

)=

g ′(x)h(x)− g(x)h′(x)

h(x)2

This is annoying to remember (where does that minus sign goagain?). Luckily we can notice

g(x)

h(x)= g(x)k(x) where k(x) = (h(x))−1

So we can just use the product rule!

Page 42: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

The quotient rule is stupid

The quotient rule says

ddx

(g(x)

h(x)

)=

g ′(x)h(x)− g(x)h′(x)

h(x)2

This is annoying to remember (where does that minus sign goagain?). Luckily we can notice

g(x)

h(x)= g(x)k(x) where k(x) = (h(x))−1

So we can just use the product rule!

Page 43: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) = sin1x

SolutionWe should use the chain rule. Notice f (x) = g(h(x)) where

h(x) = x−1 and g(x) = sin x

soh′(x) = −x−2 and g ′(x) = cos x

so

f ′(x) = h′(x)g ′(h(x))

= − 1x2 cos(x−1)

Page 44: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) = sin1x

SolutionWe should use the chain rule. Notice f (x) = g(h(x)) where

h(x) = x−1 and g(x) = sin x

soh′(x) = −x−2 and g ′(x) = cos x

so

f ′(x) = h′(x)g ′(h(x))

= − 1x2 cos(x−1)

Page 45: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) = sin1x

SolutionWe should use the chain rule. Notice f (x) = g(h(x)) where

h(x) = x−1 and g(x) = sin x

soh′(x) = −x−2 and g ′(x) = cos x

so

f ′(x) = h′(x)g ′(h(x))

= − 1x2 cos(x−1)

Page 46: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) = sin1x

SolutionWe should use the chain rule. Notice f (x) = g(h(x)) where

h(x) = x−1 and g(x) = sin x

soh′(x) = −x−2 and g ′(x) = cos x

so

f ′(x) = h′(x)g ′(h(x))

= − 1x2 cos(x−1)

Page 47: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) = sin1x

SolutionWe should use the chain rule. Notice f (x) = g(h(x)) where

h(x) = x−1 and g(x) = sin x

soh′(x) = −x−2 and g ′(x) = cos x

so

f ′(x) = h′(x)g ′(h(x))

= − 1x2 cos(x−1)

Page 48: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) =x − 1x + 1

= (x − 1)(x + 1)−1

SolutionWe should use the product/quotient rule. Notice f (x) = g(x)h(x)where

h(x) = (x + 1)−1 and g(x) = x − 1

h′(x) = −(x + 1)−2 and g ′(x) = 1

so

f ′(x) = g ′(x)h(x) + g(x)h′(x)

=1

x + 1− x − 1

(x + 1)2=

2(x + 1)2

Page 49: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) =x − 1x + 1

= (x − 1)(x + 1)−1

SolutionWe should use the product/quotient rule. Notice f (x) = g(x)h(x)where

h(x) = (x + 1)−1 and g(x) = x − 1

h′(x) = −(x + 1)−2 and g ′(x) = 1

so

f ′(x) = g ′(x)h(x) + g(x)h′(x)

=1

x + 1− x − 1

(x + 1)2=

2(x + 1)2

Page 50: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) =x − 1x + 1

= (x − 1)(x + 1)−1

SolutionWe should use the product/quotient rule. Notice f (x) = g(x)h(x)where

h(x) = (x + 1)−1 and g(x) = x − 1

h′(x) = −(x + 1)−2 and g ′(x) = 1

so

f ′(x) = g ′(x)h(x) + g(x)h′(x)

=1

x + 1− x − 1

(x + 1)2=

2(x + 1)2

Page 51: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) =x − 1x + 1

= (x − 1)(x + 1)−1

SolutionWe should use the product/quotient rule. Notice f (x) = g(x)h(x)where

h(x) = (x + 1)−1 and g(x) = x − 1

h′(x) = −(x + 1)−2 and g ′(x) = 1

so

f ′(x) = g ′(x)h(x) + g(x)h′(x)

=1

x + 1− x − 1

(x + 1)2=

2(x + 1)2

Page 52: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

f (x) =x − 1x + 1

= (x − 1)(x + 1)−1

SolutionWe should use the product/quotient rule. Notice f (x) = g(x)h(x)where

h(x) = (x + 1)−1 and g(x) = x − 1

h′(x) = −(x + 1)−2 and g ′(x) = 1

so

f ′(x) = g ′(x)h(x) + g(x)h′(x)

=1

x + 1− x − 1

(x + 1)2=

2(x + 1)2

Page 53: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

F (x) =sin x2 − 1sin x2 + 1

SolutionWe should notice that F(x) = f(g(x)) so we can use the chain rule!

f (x) =x − 1x + 1

and g(x) = sin x2

f ′(x) =2

(x + 1)2and g ′(x) = 2x cos x2

so

f ′(x) = g ′(x)f ′(g(x))

= 2x cos x2 2(sin x2 + 1)2

Page 54: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

F (x) =sin x2 − 1sin x2 + 1

SolutionWe should notice that F(x) = f(g(x)) so we can use the chain rule!

f (x) =x − 1x + 1

and g(x) = sin x2

f ′(x) =2

(x + 1)2and g ′(x) = 2x cos x2

so

f ′(x) = g ′(x)f ′(g(x))

= 2x cos x2 2(sin x2 + 1)2

Page 55: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

F (x) =sin x2 − 1sin x2 + 1

SolutionWe should notice that F(x) = f(g(x)) so we can use the chain rule!

f (x) =x − 1x + 1

and g(x) = sin x2

f ′(x) =2

(x + 1)2and g ′(x) = 2x cos x2

so

f ′(x) = g ′(x)f ′(g(x))

= 2x cos x2 2(sin x2 + 1)2

Page 56: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

F (x) =sin x2 − 1sin x2 + 1

SolutionWe should notice that F(x) = f(g(x)) so we can use the chain rule!

f (x) =x − 1x + 1

and g(x) = sin x2

f ′(x) =2

(x + 1)2and g ′(x) = 2x cos x2

so

f ′(x) = g ′(x)f ′(g(x))

= 2x cos x2 2(sin x2 + 1)2

Page 57: Math 3B: Lecture 1 · 2017-10-04 · InstructorandTAs Instructor NoahWhite officehours MS6304,W,F10:30am-12pm TA MaxZhou officehours TBA,TBA YuejiaoSun TBA,TBA MengyuanDing TBA,TBA

Example

QuestionDifferentiate

F (x) =sin x2 − 1sin x2 + 1

SolutionWe should notice that F(x) = f(g(x)) so we can use the chain rule!

f (x) =x − 1x + 1

and g(x) = sin x2

f ′(x) =2

(x + 1)2and g ′(x) = 2x cos x2

so

f ′(x) = g ′(x)f ′(g(x))

= 2x cos x2 2(sin x2 + 1)2