Year 11 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 4 — 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 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) = 2x + 3, find f(1).
Answer: 5
- Replace x with 1: 2(1) + 3
- = 5
2.If f(x) = 2x + 7, find f(4).
Answer: 15
- Replace x with 4: 2(4) + 7
- = 15
3.If f(x) = 4x2 − 3x − 5, find f(3).
Answer: 22
- Replace x with 3: 4(3)2 − 3(3) − 5
- = 22
4.If f(x) = −5x − 1, find f(2).
Answer: −11
- Replace x with 2: −5(2) − 1
- = −11
5.If f(x) = −x + 4, find f(0).
Answer: 4
- Replace x with 0: −(0) + 4
- = 4
6.If f(x) = 3x2 − 2x + 8, find f(−4).
Answer: 64
- Replace x with −4: 3(−4)2 − 2(−4) + 8
- = 64
7.If f(x) = −x2 + 3x + 8, find f(0).
Answer: 8
- Replace x with 0: −(0)2 + 3(0) + 8
- = 8
8.If f(x) = 3x2 + 3x − 6, find f(5).
Answer: 84
- Replace x with 5: 3(5)2 + 3(5) − 6
- = 84
9.If f(x) = 4x2 − 5x + 2, find f(−1).
Answer: 11
- Replace x with −1: 4(−1)2 − 5(−1) + 2
- = 11
10.If f(x) = −2x2 + 6x + 5, find f(−4).
Answer: −51
- Replace x with −4: −2(−4)2 + 6(−4) + 5
- = −51
11.If f(x) = −x2 − 6x + 2, find f(−2).
Answer: 10
- Replace x with −2: −(−2)2 − 6(−2) + 2
- = 10
12.If f(x) = −5x + 6, find f(−3).
Answer: 21
- Replace x with −3: −5(−3) + 6
- = 21
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