Year 12 Integration (Polynomials) Worksheet — Level 3 — Practice Set 2 — Answers
Answer sheet with worked solutions for the Year 12 calculus worksheet.
Year 12 Integration (Polynomials) Worksheet — Level 3 — Practice Set 2 — Answers
Use the rule ∫ xⁿ dx = xⁿ⁺¹ / (n+1) + C.
1.Find ∫ (10x4 − 2x + 1) dx
Answer: 2x5 − x2 + x + C
- ∫ 10x4 dx = 2x5
- ∫ −2x dx = −x2
- ∫ 1 dx = x
- Don't forget the constant of integration, C
2.Evaluate ∫ from 1 to 2 of (−5x4 − 4x + 2) dx
Answer: −35
- ∫ −5x4 dx = −x5
- ∫ −4x dx = −2x2
- ∫ 2 dx = 2x
- F(x) = −x5 − 2x2 + 2x
- F(2) − F(1) = −36 − (−1) = −35
3.Evaluate ∫ from 0 to 3 of (−10x4 − 9x2 − 6x) dx
Answer: −594
- ∫ −10x4 dx = −2x5
- ∫ −9x2 dx = −3x3
- ∫ −6x dx = −3x2
- F(x) = −2x5 − 3x3 − 3x2
- F(3) − F(0) = −594 − (0) = −594
4.Find ∫ (12x3 + 4x + 4) dx
Answer: 3x4 + 2x2 + 4x + C
- ∫ 12x3 dx = 3x4
- ∫ 4x dx = 2x2
- ∫ 4 dx = 4x
- Don't forget the constant of integration, C
5.Evaluate ∫ from 2 to 3 of (6x2 − 4x + 4) dx
Answer: 32
- ∫ 6x2 dx = 2x3
- ∫ −4x dx = −2x2
- ∫ 4 dx = 4x
- F(x) = 2x3 − 2x2 + 4x
- F(3) − F(2) = 48 − (16) = 32
6.Evaluate ∫ from 0 to 1 of (−5x4 − 8x3 − 2) dx
Answer: −5
- ∫ −5x4 dx = −x5
- ∫ −8x3 dx = −2x4
- ∫ −2 dx = −2x
- F(x) = −x5 − 2x4 − 2x
- F(1) − F(0) = −5 − (0) = −5
7.Evaluate ∫ from 0 to 3 of (20x4 + 8x3 + 3) dx
Answer: 1143
- ∫ 20x4 dx = 4x5
- ∫ 8x3 dx = 2x4
- ∫ 3 dx = 3x
- F(x) = 4x5 + 2x4 + 3x
- F(3) − F(0) = 1143 − (0) = 1143
8.Find ∫ (−10x4 − 8x3 − 2x) dx
Answer: −2x5 − 2x4 − x2 + C
- ∫ −10x4 dx = −2x5
- ∫ −8x3 dx = −2x4
- ∫ −2x dx = −x2
- Don't forget the constant of integration, C
9.Find ∫ (20x4 + 6x + 2) dx
Answer: 4x5 + 3x2 + 2x + C
- ∫ 20x4 dx = 4x5
- ∫ 6x dx = 3x2
- ∫ 2 dx = 2x
- Don't forget the constant of integration, C
10.Find ∫ (−5x4 − 4x3 + 9x2) dx
Answer: −x5 − x4 + 3x3 + C
- ∫ −5x4 dx = −x5
- ∫ −4x3 dx = −x4
- ∫ 9x2 dx = 3x3
- 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.
- 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.