Take the ECAT Mathematics — Integration (Set 5): 30 multiple-choice questions (40 minutes) with instant scoring and a full answer review. Covers 30 ECAT…
The first 5 questions of this test, with the correct answer and explanation.
Q1. ∫ x/√(x + 1) dx equals:
- A. 2(x + 1)^(3/2)/3 − 2√(x + 1) + C ✓
- B. 2(x + 1)^(3/2)/3 + 2√(x + 1) + C
- C. 2x √(x + 1) + C
- D. 2(x + 1)^(3/2)/3 − √(x + 1) + C
Answer: A. 2(x + 1)^(3/2)/3 − 2√(x + 1) + C
Explanation: Put u = x + 1: ∫ (u − 1)u^(−1/2) du = (2/3)u^(3/2) − 2u^(1/2).
Q2. ∫ dx/[x(x + 1)²] (x > 0) equals:
- A. ln(x/(x + 1)) + 1/(x + 1) + C ✓
- B. ln(x(x + 1)) + 1/(x + 1) + C
- C. ln x − 1/(x + 1)² + C
- D. ln(x/(x + 1)) − 1/(x + 1) + C
Answer: A. ln(x/(x + 1)) + 1/(x + 1) + C
Explanation: 1/[x(x + 1)²] = 1/x − 1/(x + 1) − 1/(x + 1)², so the integral is ln x − ln(x + 1) + 1/(x + 1).
Q3. ∫ sin x cos x/(1 + sin²x) dx equals:
- A. ln(1 + sin²x) + C
- B. tan⁻¹(sin x) + C
- C. ln(1 + sin²x)/2 + C ✓
- D. −ln(1 + sin²x)/2 + C
Answer: C. ln(1 + sin²x)/2 + C
Explanation: Put u = 1 + sin²x, du = 2 sin x cos x dx: ½ ln u.
Q4. ∫ eˣ/√(1 − e²ˣ) dx equals:
- A. sin⁻¹ eˣ + C ✓
- B. √(1 − e^(2x)) + C
- C. cos⁻¹ eˣ + C
- D. tan⁻¹ eˣ + C
Answer: A. sin⁻¹ eˣ + C
Explanation: Put u = eˣ: ∫ du/√(1 − u²) = sin⁻¹u.
Q5. ∫ x²/(1 + x⁶) dx equals:
- A. tan⁻¹(x³) + C
- B. tan⁻¹(x³)/9 + C
- C. ln(1 + x⁶)/6 + C
- D. tan⁻¹(x³)/3 + C ✓
Answer: D. tan⁻¹(x³)/3 + C
Explanation: Put u = x³, du = 3x² dx: (1/3)∫ du/(1 + u²) = (1/3)tan⁻¹(x³).
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Q6. ∫ x sec x tan x dx on (0, π/2) equals:
- A. x sec x + ln(sec x + tan x) + C
- B. x tan x − ln(sec x) + C
- C. x sec x − ln(sec x + tan x) + C
- D. sec x − x ln(sec x + tan x) + C
Q7. ∫ ln(x² + 1) dx equals:
- A. x ln(x² + 1) − 2x − 2 tan⁻¹ x + C
- B. x ln(x² + 1) + 2 tan⁻¹ x − x + C
- C. x ln(x² + 1) − 2x + C
- D. x ln(x² + 1) − 2x + 2 tan⁻¹ x + C
Q8. ∫ sec⁴x dx equals:
- A. tan x + tan³x + C
- B. tan³x/3 + C
- C. tan x + tan³x/3 + C
- D. sec⁵x/5 + C
Q9. ∫ dx/(1 − cos x) equals:
- A. cot(x/2) + C
- B. −cot(x/2) + C
- C. −cot x + C
- D. −tan(x/2) + C
Q10. ∫ x e^(2x) dx equals:
- A. x e^(2x)/2 + C
- B. e^(2x)(x − 1/2) + C
- C. e^(2x)(x/2 + 1/4) + C
- D. e^(2x)(x/2 − 1/4) + C
Q11. ∫ x³e^(x²) dx equals:
- A. x² e^(x²)/2 + C
- B. e^(x²)(x² + 1)/2 + C
- C. e^(x²)(x² − 1)/2 + C
- D. e^(x²)(x² − 1) + C
Q12. ∫ dx/[x√(x² − 1)] for x > 1 equals:
- A. ln(x + √(x² − 1)) + C
- B. √(x² − 1)/x + C
- C. sin⁻¹ x + C
- D. sec⁻¹ x + C
Q13. ∫ (x + 2)/(x² + 4x + 7) dx equals:
- A. ln(x² + 4x + 7) + C
- B. ln(x² + 4x + 7)/4 + C
- C. tan⁻¹((x + 2)/√3)/√3 + C
- D. ln(x² + 4x + 7)/2 + C
Q14. ∫ dx/(x² + x + 1) equals:
- A. tan⁻¹((2x + 1)/√3)/√3 + C
- B. tan⁻¹(x + 1/2) + C
- C. 2 tan⁻¹((2x + 1)/√3) + C
- D. 2 tan⁻¹((2x + 1)/√3)/√3 + C
Q15. ∫ 2ˣ·3ˣ dx equals:
- A. 6ˣ/ln 6 + C
- B. 6ˣ + C
- C. x 6^(x − 1) + C
- D. 6ˣ ln 6 + C
Q16. ∫ dx/[√x(1 + √x)] equals:
- A. 2√x ln(1 + √x) + C
- B. ln(1 + √x) + C
- C. 2 ln(1 + √x) + C
- D. 2 tan⁻¹(√x) + C
Q17. ∫ sin⁻¹x/√(1 − x²) dx equals:
- A. x sin⁻¹ x + C
- B. (sin⁻¹x)³/3 + C
- C. (sin⁻¹x)²/2 + C
- D. (sin⁻¹x)² + C
Q18. ∫ e⁻ˣ cos x dx equals:
- A. e⁻ˣ(sin x − cos x)/2 + C
- B. e⁻ˣ(cos x − sin x)/2 + C
- C. e⁻ˣ(sin x − cos x) + C
- D. e⁻ˣ(sin x + cos x)/2 + C
Q19. ∫ x/(1 + x⁴) dx equals:
- A. tan⁻¹(x²)/2 + C
- B. tan⁻¹(x²) + C
- C. ln(1 + x⁴)/4 + C
- D. tan⁻¹(x²)/4 + C
Q20. ∫ sinh²x dx equals:
- A. sinh 2x/2 − x/2 + C
- B. sinh 2x/4 + x/2 + C
- C. sinh³x/3 + C
- D. sinh 2x/4 − x/2 + C
Q21. ∫ cos x/√(1 + sin x) dx equals:
- A. 2√(1 + sin x)/3 + C
- B. ln(1 + sin x) + C
- C. 2√(1 + sin x) + C
- D. √(1 + sin x) + C
Q22. If ∫ f(x) dx = g(x) + C, then ∫ x f(x²) dx equals:
- A. ½ g(x²) + C
- B. g(x²) + C
- C. ½ x g(x²) + C
- D. 2x g(x²) + C
Q23. ∫ x³/(x + 1) dx equals:
- A. x³/3 + x²/2 + x − ln(x + 1) + C
- B. x³/3 − x²/2 + x + ln(x + 1) + C
- C. x³/3 − x²/2 + x − 1/(x + 1) + C
- D. x³/3 − x²/2 + x − ln(x + 1) + C
Q24. ∫ sec x (sec x + tan x) dx equals:
- A. tan x − sec x + C
- B. tan x + sec x + C
- C. sec x tan x + C
- D. tan x + ln(sec x + tan x) + C
Q25. ∫ cos 2x/(sin²x cos²x) dx equals:
- A. −cot x + tan x + C
- B. −cot x − tan x + C
- C. cot x + tan x + C
- D. cot x − tan x + C
Q26. ∫ dx/√(2x − x²) equals:
- A. cos⁻¹(x − 1) + C
- B. sin⁻¹(x/2) + C
- C. sin⁻¹ x + C
- D. sin⁻¹(x − 1) + C
Q27. ∫ x√(1 − x) dx equals:
- A. x² √(1 − x)/2 + C
- B. −2(1 − x)^(3/2)/3 − 2(1 − x)^(5/2)/5 + C
- C. 2(1 − x)^(3/2)/3 − 2(1 − x)^(5/2)/5 + C
- D. −2(1 − x)^(3/2)/3 + 2(1 − x)^(5/2)/5 + C
Q28. ∫ ln(e^(x²)) dx equals:
- A. 2x³/3 + C
- B. x³/3 + C
- C. x²/2 + C
- D. x³ + C
Q29. ∫ sin(ln x)/x dx (x > 0) equals:
- A. cos(ln x) + C
- B. −cos(ln x) + C
- C. −cos(ln x)/x + C
- D. ln x sin(ln x) + C
Q30. The function F with F′(x) = x eˣ and F(0) = 0 is:
- A. (x − 1) eˣ
- B. (x + 1) eˣ − 1
- C. (x − 1) eˣ + 1
- D. x eˣ + 1