Year 10 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 3 — 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 3 — 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) = −x − 1, find f(0).
Answer: −1
- Replace x with 0: −(0) − 1
- = −1
2.If f(x) = x, find f(−1).
Answer: −1
- Replace x with −1: (−1)
- = −1
3.If f(x) = 6x + 9, find f(4).
Answer: 33
- Replace x with 4: 6(4) + 9
- = 33
4.If f(x) = 4x2 + 2x − 5, find f(−1).
Answer: −3
- Replace x with −1: 4(−1)2 + 2(−1) − 5
- = −3
5.If f(x) = −4x − 4, find f(5).
Answer: −24
- Replace x with 5: −4(5) − 4
- = −24
6.If f(x) = 2x2 + 6x + 4, find f(5).
Answer: 84
- Replace x with 5: 2(5)2 + 6(5) + 4
- = 84
7.If f(x) = −6x, find f(1).
Answer: −6
- Replace x with 1: −6(1)
- = −6
8.If f(x) = 2x2 − 9, find f(5).
Answer: 41
- Replace x with 5: 2(5)2 − 9
- = 41
9.If f(x) = 6x + 9, find f(−1).
Answer: 3
- Replace x with −1: 6(−1) + 9
- = 3
10.If f(x) = −3x2 + x + 6, find f(0).
Answer: 6
- Replace x with 0: −3(0)2 + (0) + 6
- = 6
11.If f(x) = 3x + 4, find f(2).
Answer: 10
- Replace x with 2: 3(2) + 4
- = 10
12.If f(x) = 2x + 4, find f(4).
Answer: 12
- Replace x with 4: 2(4) + 4
- = 12
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