Year 11 Integration (Polynomials) Worksheet — Level 3 — Practice Set 4 — Answers
Answer sheet with worked solutions for the Year 11 calculus worksheet.
Year 11 Integration (Polynomials) Worksheet — Level 3 — Practice Set 4 — Answers
Use the rule ∫ xⁿ dx = xⁿ⁺¹ / (n+1) + C.
1.Find ∫ (5x4 − 9x2 + 2) dx
Answer: x5 − 3x3 + 2x + C
- ∫ 5x4 dx = x5
- ∫ −9x2 dx = −3x3
- ∫ 2 dx = 2x
- Don't forget the constant of integration, C
2.Evaluate ∫ from 0 to 2 of (10x4 − 12x3 + 3) dx
Answer: 22
- ∫ 10x4 dx = 2x5
- ∫ −12x3 dx = −3x4
- ∫ 3 dx = 3x
- F(x) = 2x5 − 3x4 + 3x
- F(2) − F(0) = 22 − (0) = 22
3.Find ∫ (−10x4 + 4x3 − 9x2) dx
Answer: −2x5 + x4 − 3x3 + C
- ∫ −10x4 dx = −2x5
- ∫ 4x3 dx = x4
- ∫ −9x2 dx = −3x3
- Don't forget the constant of integration, C
4.Evaluate ∫ from 2 to 4 of (15x4 + 12x2 − 4x) dx
Answer: 3176
- ∫ 15x4 dx = 3x5
- ∫ 12x2 dx = 4x3
- ∫ −4x dx = −2x2
- F(x) = 3x5 + 4x3 − 2x2
- F(4) − F(2) = 3296 − (120) = 3176
5.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
6.Evaluate ∫ from 1 to 3 of (15x4 + 12x3 − 2x) dx
Answer: 958
- ∫ 15x4 dx = 3x5
- ∫ 12x3 dx = 3x4
- ∫ −2x dx = −x2
- F(x) = 3x5 + 3x4 − x2
- F(3) − F(1) = 963 − (5) = 958
7.Evaluate ∫ from 2 to 5 of (−15x4 + 6x + 4) dx
Answer: −9204
- ∫ −15x4 dx = −3x5
- ∫ 6x dx = 3x2
- ∫ 4 dx = 4x
- F(x) = −3x5 + 3x2 + 4x
- F(5) − F(2) = −9280 − (−76) = −9204
8.Evaluate ∫ from 2 to 3 of (8x3 − 2x + 1) dx
Answer: 126
- ∫ 8x3 dx = 2x4
- ∫ −2x dx = −x2
- ∫ 1 dx = x
- F(x) = 2x4 − x2 + x
- F(3) − F(2) = 156 − (30) = 126
9.Find ∫ (10x4 + 3x2 + 8x) dx
Answer: 2x5 + x3 + 4x2 + C
- ∫ 10x4 dx = 2x5
- ∫ 3x2 dx = x3
- ∫ 8x dx = 4x2
- Don't forget the constant of integration, C
10.Evaluate ∫ from 0 to 3 of (20x4 + 12x2 + 8x) dx
Answer: 1116
- ∫ 20x4 dx = 4x5
- ∫ 12x2 dx = 4x3
- ∫ 8x dx = 4x2
- F(x) = 4x5 + 4x3 + 4x2
- F(3) − F(0) = 1116 − (0) = 1116
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.