Year 11 Integration (Polynomials) Worksheet — Level 3 — Practice Set 3 — Answers
Answer sheet with worked solutions for the Year 11 calculus worksheet.
Year 11 Integration (Polynomials) Worksheet — Level 3 — Practice Set 3 — Answers
Use the rule ∫ xⁿ dx = xⁿ⁺¹ / (n+1) + C.
1.Find ∫ (−5x4 + 3x2 + 6x) dx
Answer: −x5 + x3 + 3x2 + C
- ∫ −5x4 dx = −x5
- ∫ 3x2 dx = x3
- ∫ 6x dx = 3x2
- Don't forget the constant of integration, C
2.Evaluate ∫ from 2 to 4 of (−15x4 + 2x + 2) dx
Answer: −2960
- ∫ −15x4 dx = −3x5
- ∫ 2x dx = x2
- ∫ 2 dx = 2x
- F(x) = −3x5 + x2 + 2x
- F(4) − F(2) = −3048 − (−88) = −2960
3.Find ∫ (16x3 − 6x + 3) dx
Answer: 4x4 − 3x2 + 3x + C
- ∫ 16x3 dx = 4x4
- ∫ −6x dx = −3x2
- ∫ 3 dx = 3x
- Don't forget the constant of integration, C
4.Find ∫ (−4x3 − 6x2 + 1) dx
Answer: −x4 − 2x3 + x + C
- ∫ −4x3 dx = −x4
- ∫ −6x2 dx = −2x3
- ∫ 1 dx = x
- Don't forget the constant of integration, C
5.Evaluate ∫ from 0 to 2 of (15x4 + 4x − 2) dx
Answer: 100
- ∫ 15x4 dx = 3x5
- ∫ 4x dx = 2x2
- ∫ −2 dx = −2x
- F(x) = 3x5 + 2x2 − 2x
- F(2) − F(0) = 100 − (0) = 100
6.Evaluate ∫ from 0 to 2 of (−5x4 + 4x + 3) dx
Answer: −18
- ∫ −5x4 dx = −x5
- ∫ 4x dx = 2x2
- ∫ 3 dx = 3x
- F(x) = −x5 + 2x2 + 3x
- F(2) − F(0) = −18 − (0) = −18
7.Find ∫ (−12x3 − 6x2 − 3) dx
Answer: −3x4 − 2x3 − 3x + C
- ∫ −12x3 dx = −3x4
- ∫ −6x2 dx = −2x3
- ∫ −3 dx = −3x
- Don't forget the constant of integration, C
8.Evaluate ∫ from 1 to 2 of (−4x3 + 6x2 − 3) dx
Answer: −4
- ∫ −4x3 dx = −x4
- ∫ 6x2 dx = 2x3
- ∫ −3 dx = −3x
- F(x) = −x4 + 2x3 − 3x
- F(2) − F(1) = −6 − (−2) = −4
9.Evaluate ∫ from 1 to 2 of (16x3 − 9x2 − 3) dx
Answer: 36
- ∫ 16x3 dx = 4x4
- ∫ −9x2 dx = −3x3
- ∫ −3 dx = −3x
- F(x) = 4x4 − 3x3 − 3x
- F(2) − F(1) = 34 − (−2) = 36
10.Find ∫ (16x3 − 6x2 − 4x) dx
Answer: 4x4 − 2x3 − 2x2 + C
- ∫ 16x3 dx = 4x4
- ∫ −6x2 dx = −2x3
- ∫ −4x dx = −2x2
- Don't forget the constant of integration, C
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
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