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) = 4x + 9, find f(−2).
Answer: 1
- Replace x with −2: 4(−2) + 9
- = 1
2.If f(x) = −5x − 4, find f(−3).
Answer: 11
- Replace x with −3: −5(−3) − 4
- = 11
3.If f(x) = 2x − 1, find f(−1).
Answer: −3
- Replace x with −1: 2(−1) − 1
- = −3
4.If f(x) = 6x − 4, find f(3).
Answer: 14
- Replace x with 3: 6(3) − 4
- = 14
5.If f(x) = 5x − 7, find f(5).
Answer: 18
- Replace x with 5: 5(5) − 7
- = 18
6.If f(x) = 2x − 1, find f(2).
Answer: 3
- Replace x with 2: 2(2) − 1
- = 3
7.If f(x) = 3x2 − x + 1, find f(1).
Answer: 3
- Replace x with 1: 3(1)2 − (1) + 1
- = 3
8.If f(x) = 5x + 5, find f(3).
Answer: 20
- Replace x with 3: 5(3) + 5
- = 20
9.If f(x) = 2x2 + 6x − 6, find f(0).
Answer: −6
- Replace x with 0: 2(0)2 + 6(0) − 6
- = −6
10.If f(x) = 2x − 8, find f(0).
Answer: −8
- Replace x with 0: 2(0) − 8
- = −8
11.If f(x) = −3x − 8, find f(5).
Answer: −23
- Replace x with 5: −3(5) − 8
- = −23
12.If f(x) = −x2 + 7, find f(0).
Answer: 7
- Replace x with 0: −(0)2 + 7
- = 7
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