12th Grade Function Notation, Composites and Inverses Worksheet — Level 1 — Practice Set 3 — Answers
Answer sheet with worked solutions for the 12th Grade functions worksheet.
Success TutoringWorksheetsAnswer sheet12th Grade · Mathematics · Functions12th Grade 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) = x2 − 3x, find f(3).
Answer: 0
- Replace x with 3: (3)2 − 3(3)
- = 0
2.If f(x) = −3x2 + 1, find f(5).
Answer: −74
- Replace x with 5: −3(5)2 + 1
- = −74
3.If f(x) = 4x2 + x + 6, find f(−2).
Answer: 20
- Replace x with −2: 4(−2)2 + (−2) + 6
- = 20
4.If f(x) = −x2 − 5x − 4, find f(−2).
Answer: 2
- Replace x with −2: −(−2)2 − 5(−2) − 4
- = 2
5.If f(x) = −x2 − 5x + 7, find f(1).
Answer: 1
- Replace x with 1: −(1)2 − 5(1) + 7
- = 1
6.If f(x) = −2x + 7, find f(2).
Answer: 3
- Replace x with 2: −2(2) + 7
- = 3
7.If f(x) = −x − 2, find f(1).
Answer: −3
- Replace x with 1: −(1) − 2
- = −3
8.If f(x) = −5x − 1, find f(5).
Answer: −26
- Replace x with 5: −5(5) − 1
- = −26
9.If f(x) = −4x − 8, find f(2).
Answer: −16
- Replace x with 2: −4(2) − 8
- = −16
10.If f(x) = 2x − 4, find f(2).
Answer: 0
- Replace x with 2: 2(2) − 4
- = 0
11.If f(x) = −5x + 7, find f(4).
Answer: −13
- Replace x with 4: −5(4) + 7
- = −13
12.If f(x) = 2x2 + 4x + 9, find f(−4).
Answer: 25
- Replace x with −4: 2(−4)2 + 4(−4) + 9
- = 25
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