Determine function type:
Since we have a variable with no exponents:this is a linear function
Since this is a linear function
it is a direct variation equation. The constant of proportionality is 4/5
Now Plot points from 10 to -10
| x | Plug in x | ƒ(x) = 4/5x | Ordered Pair |
|---|---|---|---|
| -10 | 4/5(-10) | -8 | (-10, -8) |
| -9 | 4/5(-9) | -7.2 | (-9, -7.2) |
| -8 | 4/5(-8) | -6.4 | (-8, -6.4) |
| -7 | 4/5(-7) | -5.6 | (-7, -5.6) |
| -6 | 4/5(-6) | -4.8 | (-6, -4.8) |
| -5 | 4/5(-5) | -4 | (-5, -4) |
| -4 | 4/5(-4) | -3.2 | (-4, -3.2) |
| -3 | 4/5(-3) | -2.4 | (-3, -2.4) |
| -2 | 4/5(-2) | -1.6 | (-2, -1.6) |
| -1 | 4/5(-1) | -0.8 | (-1, -0.8) |
| 0 | 4/5(0) | 0 | (0, 0) |
| 1 | 4/5(1) | 0.8 | (1, 0.8) |
| 2 | 4/5(2) | 1.6 | (2, 1.6) |
| 3 | 4/5(3) | 2.4 | (3, 2.4) |
| 4 | 4/5(4) | 3.2 | (4, 3.2) |
| 5 | 4/5(5) | 4 | (5, 4) |
| 6 | 4/5(6) | 4.8 | (6, 4.8) |
| 7 | 4/5(7) | 5.6 | (7, 5.6) |
| 8 | 4/5(8) | 6.4 | (8, 6.4) |
| 9 | 4/5(9) | 7.2 | (9, 7.2) |
| 10 | 4/5(10) | 8 | (10, 8) |
Determine the y-intercept:
The y-intercept is found when x is set to 0. From the grid above, our y-intercept is 0Determine the x-intercept
The x-intercept is found when y is set to 0The y-intercept is found when y is set to 0. From the grid above, our x-intercept is 0
Determine the domain of the function:
The domain represents all values of x that you can enterThe domain is (-∞, ∞) or All Real Numbers
Determine the range of the function:
The range is all the possible values of y or ƒ(x) that can existThe range is (-∞, ∞) or All Real Numbers
(-10, -8)
(-9, -7.2)
(-8, -6.4)
(-7, -5.6)
(-6, -4.8)
(-5, -4)
(-4, -3.2)
(-3, -2.4)
(-2, -1.6)
(-1, -0.8)
(0, 0)
(1, 0.8)
(2, 1.6)
(3, 2.4)
(4, 3.2)
(5, 4)
(6, 4.8)
(7, 5.6)
(8, 6.4)
(9, 7.2)
(10, 8)
(-9, -7.2)
(-8, -6.4)
(-7, -5.6)
(-6, -4.8)
(-5, -4)
(-4, -3.2)
(-3, -2.4)
(-2, -1.6)
(-1, -0.8)
(0, 0)
(1, 0.8)
(2, 1.6)
(3, 2.4)
(4, 3.2)
(5, 4)
(6, 4.8)
(7, 5.6)
(8, 6.4)
(9, 7.2)
(10, 8)
