Year 11 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 2 — 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 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) = −3x − 4, find f(5).
Answer: −19
- Replace x with 5: −3(5) − 4
- = −19
2.If f(x) = 2x2 + x + 3, find f(3).
Answer: 24
- Replace x with 3: 2(3)2 + (3) + 3
- = 24
3.If f(x) = −3x − 6, find f(3).
Answer: −15
- Replace x with 3: −3(3) − 6
- = −15
4.If f(x) = 5x − 3, find f(2).
Answer: 7
- Replace x with 2: 5(2) − 3
- = 7
5.If f(x) = 4x2 − 4x − 4, find f(3).
Answer: 20
- Replace x with 3: 4(3)2 − 4(3) − 4
- = 20
6.If f(x) = −x + 4, find f(3).
Answer: 1
- Replace x with 3: −(3) + 4
- = 1
7.If f(x) = −4x + 4, find f(−4).
Answer: 20
- Replace x with −4: −4(−4) + 4
- = 20
8.If f(x) = −4x − 1, find f(2).
Answer: −9
- Replace x with 2: −4(2) − 1
- = −9
9.If f(x) = −3x2 + x − 3, find f(4).
Answer: −47
- Replace x with 4: −3(4)2 + (4) − 3
- = −47
10.If f(x) = −x2 − 7, find f(3).
Answer: −16
- Replace x with 3: −(3)2 − 7
- = −16
11.If f(x) = −x2 + 4x + 8, find f(0).
Answer: 8
- Replace x with 0: −(0)2 + 4(0) + 8
- = 8
12.If f(x) = 2x2 + 3x − 6, find f(1).
Answer: −1
- Replace x with 1: 2(1)2 + 3(1) − 6
- = −1
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