Year 11 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 2 — 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 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) = 3x + 2, find f(0).
Answer: 2
- Replace x with 0: 3(0) + 2
- = 2
2.If f(x) = −5x − 1, find f(3).
Answer: −16
- Replace x with 3: −5(3) − 1
- = −16
3.If f(x) = −x − 8, find f(3).
Answer: −11
- Replace x with 3: −(3) − 8
- = −11
4.If f(x) = 4x2 − 5x + 1, find f(4).
Answer: 45
- Replace x with 4: 4(4)2 − 5(4) + 1
- = 45
5.If f(x) = −3x2 − x − 7, find f(−3).
Answer: −31
- Replace x with −3: −3(−3)2 − (−3) − 7
- = −31
6.If f(x) = 3x2 + 5x + 8, find f(2).
Answer: 30
- Replace x with 2: 3(2)2 + 5(2) + 8
- = 30
7.If f(x) = −2x2 − 4x + 2, find f(−3).
Answer: −4
- Replace x with −3: −2(−3)2 − 4(−3) + 2
- = −4
8.If f(x) = −6x + 6, find f(1).
Answer: 0
- Replace x with 1: −6(1) + 6
- = 0
9.If f(x) = −3x2 − 6x, find f(1).
Answer: −9
- Replace x with 1: −3(1)2 − 6(1)
- = −9
10.If f(x) = 3x2 − 2, find f(−2).
Answer: 10
- Replace x with −2: 3(−2)2 − 2
- = 10
11.If f(x) = 3x − 7, find f(−4).
Answer: −19
- Replace x with −4: 3(−4) − 7
- = −19
12.If f(x) = 3x, find f(3).
Answer: 9
- Replace x with 3: 3(3)
- = 9
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