a) 2D Vector Conversion and Additionb) Vectors on your Calculator c) Vector addition practiced) 3D Spherical to Cartesian

ENGR 34 Chapter 2, Day 12D & 3D Vectors

2D Coordinate ConversionApproach #1 (manual):

Keep angles between 0 and 90,

sin for opposite, cos for adjacent,

do signs yourself.

Approach #2 (automatic):

Use standard defined angles,

(from x axis counter-clockwise),

input into calculator.

Vector Addition, Component Approach

• Break each vector into components

• Add components• Convert to polar?

Vector Addition, Triangle Approach

• Construct Parallelogram• Apply trigonometry

R-P, P-R Calculator Hints

• Modes: approx, degree, cylindrical• Special characters• Grab & enter• Show steps on HW & Exams

Name GameTo facilitate collaboration in all your

shared classes

3D Spherical/CartesianAvoid equations (no clear trig standard)

Keep angles between 0 and 90,

Do signs yourself,

Notice the pattern

Blue angle first: Az = A sin

Ah = A cos

Grey angle next: Ax = A coscos

Ay = A cossin

2D & 3D VectorsKey Ideas

• Become calculator experts• Avoid extra trig steps (use unit

vectors)• Be able to derive spherical

conversion