Evaluating Functions from a Graph
Evaluating Function
X-intercept & y-intercept
Domain & Range
Is it a Function?
100
Evaluate f(4) from the graph below:
f(4) = -1
100
Evaluate f(2) if f(x)=-3x
f(2) = -6
100
Find the x-intercept and y-intercept.
2x - 4y = 8
x-intercept = 4 y-intercept = -2
100
State the domain and range:
| x | y |
| 3 | 7 |
| 5 | 9 |
| 3 | 8 |
D: {3, 5} R: {7, 8, 9}
100
Is it a function? Justify your answer.
{(2, 3), (4, 5), ( -2, 6)}
Yes, each input has exactly one output.
200
Evaluate f(1) from the graph.
f(1)=1
200
Evaluate f(7) if f(x)= -(4x+2)
f(7) = -30
200
Find the x-intercept and the y-intercept :
13x + 7y = 25
x-intercept = 25/13 y-intercept = 25/7
200
State the domain and range: 
D: {1, 2, 3, 4, 5, 6} R: {-1, 0, 1, 2, 3, 6}
200
No, the input of 20 has 2 different outputs and the input of 22 has 2 different outputs
300
Evaluate f(3) from the graph.
f(3)=-1
300
Evaluate f(-6) if f(x)=x2 - 9
f(-6) = 27
300
Find the x-intercept and the y-intercept.
-8x - 3y = 24
x-intercept = -3 y-intercept = -8
300
State the domain and range: 
D: -4 ≤ x R: y∈ℝ
300
Is it a function? Justify your answer.
| x | y |
| 2 | 4 |
| 1 | 5 |
| 2 | 6 |
No, the input of 2 has two different outputs.
400
Evaluate f(0) from the graph.
f(0)=-5
400
Evaluate f(x)=9 if f(x)=25 - 4x
x = 4
400
Find the x-intercept and the y-intercept:
2/3y - 5x = 20
x-intercept = -4 y-intercept = 30
400
D: all real numbers R: y ≥ -5
400
Is it a function? Justify your answer.
Yes, it passes the Vertical Line Test.
500
Find x if f(x)=-2 from the graph.
x = 3 and -3
500
Evaluate f(-3) if f(x)=3x2+15
42
500
Find the x-intercept and the y-intercept:
-1/2x - 4/5y = 4
x-intercept = -8 y-intercept = -5
500
D: -2 ≤ x ≤ 2 R: 0 ≤ y ≤ 4
500
Is it a function? Justify your answer.
Yes. It passes the vertical line test.