Year 12 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 2 — 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 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) = −x + 1, find f(−2).
Answer: 3
- Replace x with −2: −(−2) + 1
- = 3
2.If f(x) = −2x2 + 6x − 8, find f(−4).
Answer: −64
- Replace x with −4: −2(−4)2 + 6(−4) − 8
- = −64
3.If f(x) = 2x2 − 4x − 2, find f(2).
Answer: −2
- Replace x with 2: 2(2)2 − 4(2) − 2
- = −2
4.If f(x) = −2x2 + 3x + 4, find f(−4).
Answer: −40
- Replace x with −4: −2(−4)2 + 3(−4) + 4
- = −40
5.If f(x) = 6x + 2, find f(3).
Answer: 20
- Replace x with 3: 6(3) + 2
- = 20
6.If f(x) = −5x − 5, find f(−1).
Answer: 0
- Replace x with −1: −5(−1) − 5
- = 0
7.If f(x) = 5x − 9, find f(1).
Answer: −4
- Replace x with 1: 5(1) − 9
- = −4
8.If f(x) = −3x2 − 3x − 4, find f(−1).
Answer: −4
- Replace x with −1: −3(−1)2 − 3(−1) − 4
- = −4
9.If f(x) = 3x − 3, find f(4).
Answer: 9
- Replace x with 4: 3(4) − 3
- = 9
10.If f(x) = −3x2 − 4x + 7, find f(1).
Answer: 0
- Replace x with 1: −3(1)2 − 4(1) + 7
- = 0
11.If f(x) = −4x − 2, find f(5).
Answer: −22
- Replace x with 5: −4(5) − 2
- = −22
12.If f(x) = 4x2 + 6x − 5, find f(−4).
Answer: 35
- Replace x with −4: 4(−4)2 + 6(−4) − 5
- = 35
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