Year 11 Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 3 — 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 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) = 3x2 + 5x − 3, find f(2).
Answer: 19
- Replace x with 2: 3(2)2 + 5(2) − 3
- = 19
2.If f(x) = 6x − 6, find f(−1).
Answer: −12
- Replace x with −1: 6(−1) − 6
- = −12
3.If f(x) = 2x2 + x − 5, find f(4).
Answer: 31
- Replace x with 4: 2(4)2 + (4) − 5
- = 31
4.If f(x) = 5x − 5, find f(0).
Answer: −5
- Replace x with 0: 5(0) − 5
- = −5
5.If f(x) = 4x2 + 6x + 6, find f(5).
Answer: 136
- Replace x with 5: 4(5)2 + 6(5) + 6
- = 136
6.If f(x) = x + 9, find f(4).
Answer: 13
- Replace x with 4: (4) + 9
- = 13
7.If f(x) = 2x − 9, find f(1).
Answer: −7
- Replace x with 1: 2(1) − 9
- = −7
8.If f(x) = 2x + 9, find f(3).
Answer: 15
- Replace x with 3: 2(3) + 9
- = 15
9.If f(x) = 6x + 3, find f(0).
Answer: 3
- Replace x with 0: 6(0) + 3
- = 3
10.If f(x) = x2 + 3x − 9, find f(4).
Answer: 19
- Replace x with 4: (4)2 + 3(4) − 9
- = 19
11.If f(x) = x2 + x − 9, find f(−2).
Answer: −7
- Replace x with −2: (−2)2 + (−2) − 9
- = −7
12.If f(x) = x − 6, find f(−2).
Answer: −8
- Replace x with −2: (−2) − 6
- = −8
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