Year 12 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 3 — 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 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) = −4x + 8, find f(0).
Answer: 8
- Replace x with 0: −4(0) + 8
- = 8
2.If f(x) = 5x + 4, find f(3).
Answer: 19
- Replace x with 3: 5(3) + 4
- = 19
3.If f(x) = x − 2, find f(−3).
Answer: −5
- Replace x with −3: (−3) − 2
- = −5
4.If f(x) = 2x − 6, find f(−1).
Answer: −8
- Replace x with −1: 2(−1) − 6
- = −8
5.If f(x) = −3x + 8, find f(5).
Answer: −7
- Replace x with 5: −3(5) + 8
- = −7
6.If f(x) = −2x2 + 3x + 1, find f(5).
Answer: −34
- Replace x with 5: −2(5)2 + 3(5) + 1
- = −34
7.If f(x) = −3x2 + x + 8, find f(4).
Answer: −36
- Replace x with 4: −3(4)2 + (4) + 8
- = −36
8.If f(x) = −4x + 2, find f(−2).
Answer: 10
- Replace x with −2: −4(−2) + 2
- = 10
9.If f(x) = 6x − 4, find f(0).
Answer: −4
- Replace x with 0: 6(0) − 4
- = −4
10.If f(x) = 4x2 + x + 2, find f(0).
Answer: 2
- Replace x with 0: 4(0)2 + (0) + 2
- = 2
11.If f(x) = 2x2 − 2x + 2, find f(2).
Answer: 6
- Replace x with 2: 2(2)2 − 2(2) + 2
- = 6
12.If f(x) = 3x − 7, find f(1).
Answer: −4
- Replace x with 1: 3(1) − 7
- = −4
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