Year 12 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 12 functions worksheet.
Success TutoringWorksheetsAnswer sheetYear 12 · Mathematics · FunctionsYear 12 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 2 — 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) = −2x − 7, find f(−2).
Answer: −3
- Replace x with −2: −2(−2) − 7
- = −3
2.If f(x) = −4x − 1, find f(−1).
Answer: 3
- Replace x with −1: −4(−1) − 1
- = 3
3.If f(x) = −3x − 3, find f(−2).
Answer: 3
- Replace x with −2: −3(−2) − 3
- = 3
4.If f(x) = 3x2 + 3x + 3, find f(−3).
Answer: 21
- Replace x with −3: 3(−3)2 + 3(−3) + 3
- = 21
5.If f(x) = x − 6, find f(0).
Answer: −6
- Replace x with 0: (0) − 6
- = −6
6.If f(x) = 3x2 − 2x − 1, find f(3).
Answer: 20
- Replace x with 3: 3(3)2 − 2(3) − 1
- = 20
7.If f(x) = −2x2 − x − 2, find f(−4).
Answer: −30
- Replace x with −4: −2(−4)2 − (−4) − 2
- = −30
8.If f(x) = 3x − 5, find f(2).
Answer: 1
- Replace x with 2: 3(2) − 5
- = 1
9.If f(x) = 2x − 2, find f(5).
Answer: 8
- Replace x with 5: 2(5) − 2
- = 8
10.If f(x) = 6x − 9, find f(−3).
Answer: −27
- Replace x with −3: 6(−3) − 9
- = −27
11.If f(x) = 3x2 − 4x − 8, find f(−2).
Answer: 12
- Replace x with −2: 3(−2)2 − 4(−2) − 8
- = 12
12.If f(x) = 4x − 5, find f(−1).
Answer: −9
- Replace x with −1: 4(−1) − 5
- = −9
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