11th Grade Function Notation, Composites and Inverses Worksheet — Level 2 — Practice Set 4 — Answers
Answer sheet with worked solutions for the 11th Grade functions worksheet.
Success TutoringWorksheetsAnswer sheet11th Grade · Mathematics · Functions11th Grade Function Notation, Composites and Inverses Worksheet — Level 2 — Practice Set 4 — 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.f(x) = 2x − 4 and g(x) = 3x − 5. Find f(g(x)) in simplest form.
Answer: 6x − 14
- f(g(x)) = 2(3x − 5) − 4
- = 6x − 14
2.If f(x) = 3x2 − 4x − 8, find f(−3).
Answer: 31
- Replace x with −3: 3(−3)2 − 4(−3) − 8
- = 31
3.If f(x) = 3x2 + 3x − 9, find f(−3).
Answer: 9
- Replace x with −3: 3(−3)2 + 3(−3) − 9
- = 9
4.If f(x) = −2x2 − 2x + 7, find f(4).
Answer: −33
- Replace x with 4: −2(4)2 − 2(4) + 7
- = −33
5.If f(x) = −3x2 − 3x, find f(−1).
Answer: 0
- Replace x with −1: −3(−1)2 − 3(−1)
- = 0
6.If f(x) = −3x2 − 4x − 3, find f(4).
Answer: −67
- Replace x with 4: −3(4)2 − 4(4) − 3
- = −67
7.f(x) = 3x + 2 and g(x) = −4x − 5. Find f(g(x)) in simplest form.
Answer: −12x − 13
- f(g(x)) = 3(−4x − 5) + 2
- = −12x − 13
8.f(x) = 2x + 3 and g(x) = 5x − 6. Find f(g(x)) in simplest form.
Answer: 10x − 9
- f(g(x)) = 2(5x − 6) + 3
- = 10x − 9
9.f(x) = x and g(x) = 2x + 3. Find g(f(x)) in simplest form.
Answer: 2x + 3
- g(f(x)) = 2(x) + 3
- = 2x + 3
10.If f(x) = x2 + x − 7, find f(−3).
Answer: −1
- Replace x with −3: (−3)2 + (−3) − 7
- = −1
11.f(x) = x − 5 and g(x) = −4x − 1. Find f(g(x)) in simplest form.
Answer: −4x − 6
- f(g(x)) = 1(−4x − 1) − 5
- = −4x − 6
12.If f(x) = −3x2 + 5x − 8, find f(0).
Answer: −8
- Replace x with 0: −3(0)2 + 5(0) − 8
- = −8
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