11th Grade Function Notation, Composites and Inverses Worksheet — Level 2 — Practice Set 3 — 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 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.f(x) = −4x − 1 and g(x) = −3x − 2. Find f(g(x)) in simplest form.
Answer: 12x + 7
- f(g(x)) = −4(−3x − 2) − 1
- = 12x + 7
2.If f(x) = x2 − 5x + 4, find f(3).
Answer: −2
- Replace x with 3: (3)2 − 5(3) + 4
- = −2
3.If f(x) = −x2 − 5x − 2, find f(4).
Answer: −38
- Replace x with 4: −(4)2 − 5(4) − 2
- = −38
4.f(x) = −4x − 4 and g(x) = −3x + 6. Find f(g(x)) in simplest form.
Answer: 12x − 28
- f(g(x)) = −4(−3x + 6) − 4
- = 12x − 28
5.If f(x) = 4x2 + 2x − 2, find f(4).
Answer: 70
- Replace x with 4: 4(4)2 + 2(4) − 2
- = 70
6.If f(x) = x2 − 6x − 4, find f(1).
Answer: −9
- Replace x with 1: (1)2 − 6(1) − 4
- = −9
7.f(x) = 5x − 2 and g(x) = 2x − 5. Find f(g(x)) in simplest form.
Answer: 10x − 27
- f(g(x)) = 5(2x − 5) − 2
- = 10x − 27
8.f(x) = 4x − 5 and g(x) = 4x − 1. Find f(g(x)) in simplest form.
Answer: 16x − 9
- f(g(x)) = 4(4x − 1) − 5
- = 16x − 9
9.If f(x) = −x2 + 2x + 5, find f(4).
Answer: −3
- Replace x with 4: −(4)2 + 2(4) + 5
- = −3
10.f(x) = −2x − 1 and g(x) = 5x + 3. Find g(f(x)) in simplest form.
Answer: −10x − 2
- g(f(x)) = 5(−2x − 1) + 3
- = −10x − 2
11.f(x) = −x + 1 and g(x) = −2x − 6. Find g(f(x)) in simplest form.
Answer: 2x − 8
- g(f(x)) = −2(−x + 1) − 6
- = 2x − 8
12.If f(x) = 4x2 − 3x − 9, find f(−3).
Answer: 36
- Replace x with −3: 4(−3)2 − 3(−3) − 9
- = 36
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