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1. Determine whether the relation is a function.
{(-2, -7), (3, -5), (6, -4), (9, -6), (10, -1)}
A relation between x-elements and y-elements in which a given input produces
exactly one output value always is called function.
To check if a relation is function, given set of points, we need to check if any x-
elements occur more than once. If any x-element is repeated, it isnt a function.
In this example, no x-values are repeated. Hence it is a function.
2. Find the slope of the line that goes through the given points.
(-3, -7), (9, -7)
(-3, -7) is the first point. So, x1=-3 and y1=-7.
Similarly, (9, -7) is the second point . So x2=9 and y2=-7.
Slope: m= change in y = y2-y1
change in x x2-x1
Hence, =7(7)
9(3)=
7+7
9+3=
0
12= 0
3. Find the slope of the line that goes through the given points.
(-8, 8), (-5, 2)
(-8, 8) is the first point. So, x1=-8 and y1=8.
Similarly, (-5, 2) is the second point . So x2=-5 and y2=2.
Slope: m= change in y = y2-y1
change in x x2-x1
Hence, =28
5(8)=
6
5+8=
6
3= 2
4. Determine whether the relation is a function.
{(1, -3), (1, 1), (6, -8), (9, -3), (11, -3)}
A relation between x-elements and y-elements in which a given input produces
exactly one output value always is called function.
To check if a relation is function, given set of points, we need to check if any x-
elements occur more than once. If any x-element is repeated, it isnt a function.
In this example, the x-value 1 is repeated. Hence it is not a function.
5. Find the slope of the line that goes through the given points.
(-1, 4), (5, 4)
(-1, 4) is the first point. So, x1=-1 and y1=4.
Similarly, (5, 4) is the second point . So x2=5 and y2=4.
Slope: m= change in y = y2-y1
change in x x2-x1
Hence, =44
5(1)=
0
5+1=
0
6= 0
6. Determine whether the relation is a function.
{(-6, -9), (-2, 1), (1, -1), (7, -7)}
In this example, no x-values are repeated. Hence it is a function.
7. Evaluate the function at the given value of the independent variable and
simplify.
f(x) = 4x2 + 5x - 6; f(x - 1)
f(x) = 4x2 + 5x 6
To find f(x-1), we substitute x = x - 1
f(x-1) = 4(x-1)^2 + 5(x-1) 6
f(x-1) = 4[x^2-2x+1] + 5x-5 6 f(x-1) = 4x^2 - 8x + 4 +5x 5 -6 f(x-1) = 4x^2 - 3x - 7
8. Determine whether the equation defines y as a function of x.
x = y2
To check if the function x=y^2 defines y as a function of x, we solve the equation
for y. If more than one solution is obtained, then y is not a function of x
x=y^2
y^2=x
y=
y=+ or y=- Hence, The equation y2 = x does NOT define y as a function of x because
when we solve for y we must apply the square root property, which will
leave us with TWO solutions for y.
9. Evaluate the function at the given value of the independent variable and
simplify.
f(x) = x2 - 1; f(x - 2)
f(x)= x^2-1
f(x-2) = (x-2)^2-1 f(x-2) = (x^2-4x+4) - 1 f(x-2) = x^2 - 4x + 4 - 1 f(x-2) = x^2-4x+3
10. Determine whether the relation is a function.
{(-5, -4), (-2, 9), (-1, -2), (-1, 7)}
In this example, the x-value -1 is repeated. Hence it is not a function.
11. Determine whether the equation defines y as a function of x.
x + y = 9
To check if the function x=y^2 defines y as a function of x, we solve the equation
for y.
x + y = 9
x + y -x = 9 x y = 9 - x
Hence, as each value of x has unique corresponding y value, the equation
defines y as function of x.
12. Determine whether the relation is a function.
{(-7, -1), (-7, 2), (-1, 8), (3, 3), (10, -7)}
In this example, the x-value -7 is repeated. Hence it is not a function.
13. Determine whether the equation defines y as a function of x.
x2 + y2 = 1
To check if the function x=y^2 defines y as a function of x, we solve the equation
for y. If more than one solution is obtained, then y is not a function of x
X^2 + y^2 = 1
y^2 = 1 x^2
y=1 ^2
y=+1 ^2 or y=- 1 ^2
Hence, The equation y2 = x does NOT define y as a function of x because when we solve for y we must apply the square root property, which will
leave us with TWO solutions for y.
14. Find the slope of the line that goes through the given points.
(-2, -6), (-9, -17)
(-2, -6) is the first point. So, x1=-2 and y1=-6.
Similarly, (-9, -17) is the second point . So x2=-9 and y2=-17.
Slope: m= change in y = y2-y1
change in x x2-x1
Hence, =17(6)
9(2)=
17+6
9+2=
11
7= 11/7
15. Find the slope of the line that goes through the given points.
(-7, 6), (-7, -9)
(-7, 6) is the first point. So, x1=-7 and y1=6.
Similarly, (-7, -9) is the second point . So x2=-7 and y2=-9.
Slope: m= change in y = y2-y1
change in x x2-x1
Hence, =96
7(7)=
15
0=
The line is parallel to Y-axis.
16. Find the slope of the line that goes through the given points.
(3, -5), (-9, -8)
(3, -5) is the first point. So, x1=3 and y1=-5.
Similarly, (-9, -8) is the second point . So x2=-9 and y2=-8.
Slope: m= change in y = y2-y1
change in x x2-x1
Hence, =8(5)
93=
8+5
12=
3
12=
1
4
17. Use the given conditions to write an equation for the line in point-slope
form.
Slope = 6/7, passing through (8, 7)
The point slop form is
y-y1=m(x-x1)
Here, given m=6/7 and (x1,y1)=(8,7)
Hence, the equation in point slop form is
y - 7 = 6
7(x - 8).
18. Use the given conditions to write an equation for the line in point-slope
form.
Slope = 4, passing through (-3, 7)
The point slop form is
y-y1=m(x-x1)
Here, given m=4 and (x1,y1)=(-3,7)
Hence, the equation in point slop form is
y - 7 = 4(x (-3))
y - 7=4(x+3)
19. Evaluate the function at the given value of the independent variable and
simplify.
f(x) = -3x - 8; f(-2)
f(x) = - 3x - 8
To find f(-2), we substitute x= - 2
f(-2) = -3*(-2) - 8
f(-2) = 6 8 f(-2) = -2