Worked example
If f(x) = 2x2 + 1, find f(−3).
Answer & why
Answer: 19
2 × (−3)2 + 1 = 2 × 9 + 1 = 19.
Grade 9 · Math
Evaluate a quadratic function
Evaluate a squared-variable function at signed inputs.
8 generated examples + worked example
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8 reproducible examples from this math generator. Choose New examples for another set.
Question 1
If f(x) = 5x2 + (4), what is f(-3)?
- 52
- 51
- 50
- 49
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 49
f(-3) = 5 × (-3)2 + (4) = 49.
Question 2
If f(x) = 5x2 + (2), what is f(0)?
- 0
- 2
- 5
- 6
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 2
f(0) = 5 × (0)2 + (2) = 2.
Question 3
If f(x) = 5x2 + (0), what is f(-2)?
- 24
- 20
- 19
- 23
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 20
f(-2) = 5 × (-2)2 + (0) = 20.
Question 4
If f(x) = 1x2 + (3), what is f(-2)?
- 5
- 8
- 6
- 7
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 7
f(-2) = 1 × (-2)2 + (3) = 7.
Question 5
If f(x) = 5x2 + (-3), what is f(2)?
- 19
- 16
- 21
- 17
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 17
f(2) = 5 × (2)2 + (-3) = 17.
Question 6
If f(x) = 3x2 + (1), what is f(0)?
- 2
- 0
- 1
- 4
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 1
f(0) = 3 × (0)2 + (1) = 1.
Question 7
If f(x) = 4x2 + (5), what is f(0)?
- 5
- 4
- 6
- 7
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 5
f(0) = 4 × (0)2 + (5) = 5.
Question 8
If f(x) = 2x2 + (-5), what is f(-4)?
- 27
- 28
- 31
- 30
A hint
Square the input before multiplying by the coefficient.
Answer & why
Answer: 27
f(-4) = 2 × (-4)2 + (-5) = 27.