Year 10 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 10 functions worksheet.
Success TutoringWorksheetsAnswer sheetYear 10 · Mathematics · FunctionsYear 10 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) = 4x2 + 5x + 5, find f(1).
Answer: 14
- Replace x with 1: 4(1)2 + 5(1) + 5
- = 14
2.If f(x) = −x − 8, find f(5).
Answer: −13
- Replace x with 5: −(5) − 8
- = −13
3.If f(x) = −6x + 5, find f(3).
Answer: −13
- Replace x with 3: −6(3) + 5
- = −13
4.If f(x) = 4x2 − 4x + 2, find f(1).
Answer: 2
- Replace x with 1: 4(1)2 − 4(1) + 2
- = 2
5.If f(x) = x − 3, find f(−1).
Answer: −4
- Replace x with −1: (−1) − 3
- = −4
6.If f(x) = 3x + 5, find f(0).
Answer: 5
- Replace x with 0: 3(0) + 5
- = 5
7.If f(x) = 2x − 1, find f(0).
Answer: −1
- Replace x with 0: 2(0) − 1
- = −1
8.If f(x) = −3x − 9, find f(−2).
Answer: −3
- Replace x with −2: −3(−2) − 9
- = −3
9.If f(x) = x2 + 5x + 9, find f(0).
Answer: 9
- Replace x with 0: (0)2 + 5(0) + 9
- = 9
10.If f(x) = 2x, find f(−2).
Answer: −4
- Replace x with −2: 2(−2)
- = −4
11.If f(x) = 3x2 + 5x − 7, find f(2).
Answer: 15
- Replace x with 2: 3(2)2 + 5(2) − 7
- = 15
12.If f(x) = 4x2 − 8, find f(−1).
Answer: −4
- Replace x with −1: 4(−1)2 − 8
- = −4
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