Year 11 Function Notation, Composites and Inverses Worksheet — Level 1 — 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 — 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) = 5x − 8, find f(2).
Answer: 2
- Replace x with 2: 5(2) − 8
- = 2
2.If f(x) = −x2 + 5x + 4, find f(−2).
Answer: −10
- Replace x with −2: −(−2)2 + 5(−2) + 4
- = −10
3.If f(x) = x2 − 2x − 5, find f(2).
Answer: −5
- Replace x with 2: (2)2 − 2(2) − 5
- = −5
4.If f(x) = −x + 7, find f(−3).
Answer: 10
- Replace x with −3: −(−3) + 7
- = 10
5.If f(x) = 2x2 − 3x − 2, find f(5).
Answer: 33
- Replace x with 5: 2(5)2 − 3(5) − 2
- = 33
6.If f(x) = −3x2 − 5x + 4, find f(−4).
Answer: −24
- Replace x with −4: −3(−4)2 − 5(−4) + 4
- = −24
7.If f(x) = 2x2 + 6x − 7, find f(−3).
Answer: −7
- Replace x with −3: 2(−3)2 + 6(−3) − 7
- = −7
8.If f(x) = −2x2 + 6x − 8, find f(5).
Answer: −28
- Replace x with 5: −2(5)2 + 6(5) − 8
- = −28
9.If f(x) = −x2 + 4x − 5, find f(−2).
Answer: −17
- Replace x with −2: −(−2)2 + 4(−2) − 5
- = −17
10.If f(x) = −4x + 9, find f(−1).
Answer: 13
- Replace x with −1: −4(−1) + 9
- = 13
11.If f(x) = −4x + 3, find f(−2).
Answer: 11
- Replace x with −2: −4(−2) + 3
- = 11
12.If f(x) = −2x2 + 5x + 8, find f(−4).
Answer: −44
- Replace x with −4: −2(−4)2 + 5(−4) + 8
- = −44
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