Year 12 Integration (Polynomials) Worksheet — Level 3 — Answers
Answer sheet with worked solutions for the Year 12 calculus worksheet.
Year 12 Integration (Polynomials) Worksheet — Level 3 — Answers
Use the rule ∫ xⁿ dx = xⁿ⁺¹ / (n+1) + C.
1.Find ∫ (−15x4 + 12x3 − 6x) dx
Answer: −3x5 + 3x4 − 3x2 + C
- ∫ −15x4 dx = −3x5
- ∫ 12x3 dx = 3x4
- ∫ −6x dx = −3x2
- Don't forget the constant of integration, C
2.Evaluate ∫ from 0 to 1 of (−5x4 + 2x + 3) dx
Answer: 3
- ∫ −5x4 dx = −x5
- ∫ 2x dx = x2
- ∫ 3 dx = 3x
- F(x) = −x5 + x2 + 3x
- F(1) − F(0) = 3 − (0) = 3
3.Evaluate ∫ from 0 to 1 of (12x3 + 3x2 + 8x) dx
Answer: 8
- ∫ 12x3 dx = 3x4
- ∫ 3x2 dx = x3
- ∫ 8x dx = 4x2
- F(x) = 3x4 + x3 + 4x2
- F(1) − F(0) = 8 − (0) = 8
4.Find ∫ (−4x3 + 6x2 − 2x) dx
Answer: −x4 + 2x3 − x2 + C
- ∫ −4x3 dx = −x4
- ∫ 6x2 dx = 2x3
- ∫ −2x dx = −x2
- Don't forget the constant of integration, C
5.Evaluate ∫ from 2 to 5 of (15x4 + 4x − 2) dx
Answer: 9315
- ∫ 15x4 dx = 3x5
- ∫ 4x dx = 2x2
- ∫ −2 dx = −2x
- F(x) = 3x5 + 2x2 − 2x
- F(5) − F(2) = 9415 − (100) = 9315
6.Find ∫ (3x2 + 8x + 1) dx
Answer: x3 + 4x2 + x + C
- ∫ 3x2 dx = x3
- ∫ 8x dx = 4x2
- ∫ 1 dx = x
- Don't forget the constant of integration, C
7.Evaluate ∫ from 2 to 5 of (5x4 + 8x3 − 2x) dx
Answer: 4290
- ∫ 5x4 dx = x5
- ∫ 8x3 dx = 2x4
- ∫ −2x dx = −x2
- F(x) = x5 + 2x4 − x2
- F(5) − F(2) = 4350 − (60) = 4290
8.Evaluate ∫ from 2 to 4 of (20x4 + 8x + 3) dx
Answer: 4022
- ∫ 20x4 dx = 4x5
- ∫ 8x dx = 4x2
- ∫ 3 dx = 3x
- F(x) = 4x5 + 4x2 + 3x
- F(4) − F(2) = 4172 − (150) = 4022
9.Evaluate ∫ from 2 to 5 of (5x4 − 9x2 − 3) dx
Answer: 2733
- ∫ 5x4 dx = x5
- ∫ −9x2 dx = −3x3
- ∫ −3 dx = −3x
- F(x) = x5 − 3x3 − 3x
- F(5) − F(2) = 2735 − (2) = 2733
10.Find ∫ (15x4 − 9x2 + 8x) dx
Answer: 3x5 − 3x3 + 4x2 + C
- ∫ 15x4 dx = 3x5
- ∫ −9x2 dx = −3x3
- ∫ 8x dx = 4x2
- Don't forget the constant of integration, C
Marking tips
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