Year 10 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 10 functions worksheet.
Success TutoringWorksheetsAnswer sheetYear 10 · Mathematics · FunctionsYear 10 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) = −3x − 7, find f(5).
Answer: −22
- Replace x with 5: −3(5) − 7
- = −22
2.If f(x) = 3x2 − 6x − 8, find f(5).
Answer: 37
- Replace x with 5: 3(5)2 − 6(5) − 8
- = 37
3.If f(x) = 4x2 + 5x + 1, find f(2).
Answer: 27
- Replace x with 2: 4(2)2 + 5(2) + 1
- = 27
4.If f(x) = −3x2 + 4x − 4, find f(2).
Answer: −8
- Replace x with 2: −3(2)2 + 4(2) − 4
- = −8
5.If f(x) = 4x2 + 5x + 4, find f(2).
Answer: 30
- Replace x with 2: 4(2)2 + 5(2) + 4
- = 30
6.If f(x) = 2x2 + x + 8, find f(−3).
Answer: 23
- Replace x with −3: 2(−3)2 + (−3) + 8
- = 23
7.If f(x) = 4x2 − 6x + 6, find f(−4).
Answer: 94
- Replace x with −4: 4(−4)2 − 6(−4) + 6
- = 94
8.If f(x) = −3x + 6, find f(3).
Answer: −3
- Replace x with 3: −3(3) + 6
- = −3
9.If f(x) = x + 2, find f(−3).
Answer: −1
- Replace x with −3: (−3) + 2
- = −1
10.If f(x) = 3x2 + x − 9, find f(−1).
Answer: −7
- Replace x with −1: 3(−1)2 + (−1) − 9
- = −7
11.If f(x) = 4x2 − 6, find f(−4).
Answer: 58
- Replace x with −4: 4(−4)2 − 6
- = 58
12.If f(x) = −5x − 3, find f(2).
Answer: −13
- Replace x with 2: −5(2) − 3
- = −13
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