Year 11 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 11 functions worksheet.
Success TutoringWorksheetsAnswer sheetYear 11 · Mathematics · FunctionsYear 11 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 4 — Answers
f(x) notation means "the value of the function at x". For a composite, substitute the inner function into the outer one. For an inverse, swap x and y and solve for y.
1.If f(x) = −x2 + 2x − 2, find f(1).
Answer: −1
- Replace x with 1: −(1)2 + 2(1) − 2
- = −1
2.If f(x) = 4x2 − 3x + 2, find f(−4).
Answer: 78
- Replace x with −4: 4(−4)2 − 3(−4) + 2
- = 78
3.If f(x) = −x2 + 6x + 5, find f(1).
Answer: 10
- Replace x with 1: −(1)2 + 6(1) + 5
- = 10
4.If f(x) = 5x − 8, find f(−4).
Answer: −28
- Replace x with −4: 5(−4) − 8
- = −28
5.If f(x) = −2x2 − 2x + 8, find f(−3).
Answer: −4
- Replace x with −3: −2(−3)2 − 2(−3) + 8
- = −4
6.If f(x) = x2 − 5x + 7, find f(−2).
Answer: 21
- Replace x with −2: (−2)2 − 5(−2) + 7
- = 21
7.If f(x) = −x2 + 2x + 3, find f(4).
Answer: −5
- Replace x with 4: −(4)2 + 2(4) + 3
- = −5
8.If f(x) = −2x − 2, find f(−1).
Answer: 0
- Replace x with −1: −2(−1) − 2
- = 0
9.If f(x) = 2x2 − 4x − 2, find f(2).
Answer: −2
- Replace x with 2: 2(2)2 − 4(2) − 2
- = −2
10.If f(x) = −2x − 5, find f(2).
Answer: −9
- Replace x with 2: −2(2) − 5
- = −9
11.If f(x) = 2x − 8, find f(5).
Answer: 2
- Replace x with 5: 2(5) − 8
- = 2
12.If f(x) = −3x2 + 2x + 4, find f(5).
Answer: −61
- Replace x with 5: −3(5)2 + 2(5) + 4
- = −61
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