Year 12 Function Notation, Composites and Inverses Worksheet — Level 1 — 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 — 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) = 4x2 + 5x + 8, find f(5).
Answer: 133
- Replace x with 5: 4(5)2 + 5(5) + 8
- = 133
2.If f(x) = 6x + 4, find f(1).
Answer: 10
- Replace x with 1: 6(1) + 4
- = 10
3.If f(x) = −6x, find f(5).
Answer: −30
- Replace x with 5: −6(5)
- = −30
4.If f(x) = −2x2 + 2x + 9, find f(3).
Answer: −3
- Replace x with 3: −2(3)2 + 2(3) + 9
- = −3
5.If f(x) = 3x + 4, find f(3).
Answer: 13
- Replace x with 3: 3(3) + 4
- = 13
6.If f(x) = −2x + 8, find f(−2).
Answer: 12
- Replace x with −2: −2(−2) + 8
- = 12
7.If f(x) = 2x2 − 5x + 1, find f(−2).
Answer: 19
- Replace x with −2: 2(−2)2 − 5(−2) + 1
- = 19
8.If f(x) = 2x2 − 6x − 4, find f(−4).
Answer: 52
- Replace x with −4: 2(−4)2 − 6(−4) − 4
- = 52
9.If f(x) = −3x2 + 5x + 3, find f(3).
Answer: −9
- Replace x with 3: −3(3)2 + 5(3) + 3
- = −9
10.If f(x) = −6x + 3, find f(−3).
Answer: 21
- Replace x with −3: −6(−3) + 3
- = 21
11.If f(x) = 2x2 + 2x + 8, find f(1).
Answer: 12
- Replace x with 1: 2(1)2 + 2(1) + 8
- = 12
12.If f(x) = 2x2 + 2x − 6, find f(2).
Answer: 6
- Replace x with 2: 2(2)2 + 2(2) − 6
- = 6
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