Year 12 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 4 — 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 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 + 4x − 2, find f(−4).
Answer: 46
- Replace x with −4: 4(−4)2 + 4(−4) − 2
- = 46
2.If f(x) = 3x − 6, find f(−2).
Answer: −12
- Replace x with −2: 3(−2) − 6
- = −12
3.If f(x) = 3x2 − x − 3, find f(−1).
Answer: 1
- Replace x with −1: 3(−1)2 − (−1) − 3
- = 1
4.If f(x) = −4x + 5, find f(−4).
Answer: 21
- Replace x with −4: −4(−4) + 5
- = 21
5.If f(x) = −x − 1, find f(0).
Answer: −1
- Replace x with 0: −(0) − 1
- = −1
6.If f(x) = −2x − 3, find f(−3).
Answer: 3
- Replace x with −3: −2(−3) − 3
- = 3
7.If f(x) = −2x + 4, find f(−4).
Answer: 12
- Replace x with −4: −2(−4) + 4
- = 12
8.If f(x) = 2x − 4, find f(−4).
Answer: −12
- Replace x with −4: 2(−4) − 4
- = −12
9.If f(x) = −2x − 2, find f(3).
Answer: −8
- Replace x with 3: −2(3) − 2
- = −8
10.If f(x) = 3x2 − 3x + 9, find f(−1).
Answer: 15
- Replace x with −1: 3(−1)2 − 3(−1) + 9
- = 15
11.If f(x) = 2x2 − 3x − 7, find f(2).
Answer: −5
- Replace x with 2: 2(2)2 − 3(2) − 7
- = −5
12.If f(x) = 5x + 5, find f(0).
Answer: 5
- Replace x with 0: 5(0) + 5
- = 5
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