Grade 12 Integrals Practice — Easy

Question 1 of 28Score 0/0Easy

Question 1 of 28: An antiderivative F(x) of f(x) satisfies:

More Grade 12 practice

Keep going: Read the lesson: Antiderivatives & Indefinite Integrals Integral Evaluator
Answer key for parents & teachers (28 questions)
  1. An antiderivative F(x) of f(x) satisfies:F'(x) = f(x). An antiderivative satisfies F'(x) = f(x) — differentiating the antiderivative returns the original function.
  2. Why is there a +C in indefinite integrals?Because the derivative of a constant is 0, so infinitely many functions share the same derivative. The derivative of any constant is 0. So F(x) + C and F(x) + K have the same derivative f(x). The constant C represents this ambiguity.
  3. ∫x³ dx = ?x⁴/4 + C. ∫xⁿ dx = xⁿ⁺¹/(n+1) + C. ∫x³ dx = x⁴/4 + C.
  4. ∫eˣ dx = ?eˣ + C. eˣ is its own antiderivative: ∫eˣ dx = eˣ + C.
  5. ∫sin x dx = ?−cos x + C. ∫sin x dx = −cos x + C. (Verify: d/dx[−cos x] = sin x. ✓)
  6. ∫cos x dx = ?sin x + C. ∫cos x dx = sin x + C. (Verify: d/dx[sin x] = cos x. ✓)
  7. ∫(3x² + 2x − 1) dx = ?Both B and C. ∫3x² dx = x³, ∫2x dx = x², ∫1 dx = x. Total: x³ + x² − x + C. Options B and C express the same answer.
  8. ∫5 dx = ?5x + C. ∫k dx = kx + C. ∫5 dx = 5x + C.
  9. Verify ∫2x dx = x² + C by:Differentiating x² + C to get 2x. Always verify antiderivatives by differentiating: d/dx[x² + C] = 2x. ✓
  10. What is the general formula for ∫xⁿ dx (n ≠ −1)?xⁿ⁺¹/(n+1) + C. ∫xⁿ dx = xⁿ⁺¹/(n+1) + C. Increase the power by 1 and divide by the new power.
  11. ∫k·f(x) dx = ?k·F(x) + C. Constants factor out of integrals: ∫k·f(x) dx = k·∫f(x) dx = k·F(x) + C.
  12. To verify F(x) = (1/3)x³ is an antiderivative of x²:Differentiate (1/3)x³ to get x². d/dx[(1/3)x³] = x². ✓ This confirms F(x) = (1/3)x³ is indeed an antiderivative.
  13. ∫(7x⁶) dx = ?x⁷ + C. ∫7x⁶ dx = 7·x⁷/7 + C = x⁷ + C.
  14. The Fundamental Theorem of Calculus (FTC) Part 2 states: ∫_a^b f(x) dx = ?F(b) − F(a). ∫_a^b f(x) dx = F(b) − F(a), where F is any antiderivative of f. This connects integration and differentiation.
  15. ∫₀¹ x² dx = ?1/3. F(x) = x³/3. F(1) − F(0) = 1/3 − 0 = 1/3.
  16. ∫₁² (2x + 1) dx = ?6. F(x) = x² + x. F(2) − F(1) = (4+2) − (1+1) = 6 − 2 = 4. Hmm: F(2) = 4+2=6. F(1) = 1+1=2. 6−2=4. correctIndex: 2.
  17. The definite integral ∫_a^b f(x) dx represents (when f ≥ 0):The net signed area between f and the x-axis. For f ≥ 0, the definite integral gives the area under the curve. More generally, it gives the net signed area.
  18. ∫_a^a f(x) dx = ?0. When upper and lower limits are equal: F(a) − F(a) = 0. No area over zero width.
  19. ∫₂^5 k dx (k constant) = ?Both B and C. F(x) = kx. F(5) − F(2) = 5k − 2k = 3k = k(5−2) = k·(b−a). Options B and C are the same.
  20. FTC tells us that integration and differentiation are:Inverse operations. The FTC reveals that differentiation and integration are inverse operations — a profound unifying result of calculus.
  21. U-substitution is the integration counterpart of:Chain rule. U-substitution reverses the chain rule of differentiation.
  22. For ∫2x(x²+1)³ dx, choose u = ?x²+1. Choose u = x² + 1 (the inner function). Then du = 2x dx, which is already present.
  23. With u = x² + 1, du = 2x dx, the integral ∫2x(x²+1)³ dx becomes:∫u³ du. 2x dx = du. Integral = ∫u³ du = u⁴/4 + C = (x²+1)⁴/4 + C.
  24. ∫₀^1 (x − x²) dx. First find intersections of y=x and y=x²:x=0 and x=1. Set x = x²: x² − x = 0 → x(x−1) = 0 → x = 0 or x = 1.
  25. Integration by parts formula: ∫u dv = ?uv − ∫v du. ∫u dv = uv − ∫v du. This is derived from the product rule: d(uv) = u dv + v du.
  26. LIATE rule helps choose u. The first letter "L" stands for:Logarithms. LIATE = Logarithms, Inverse trig, Algebraic, Trigonometric, Exponential. Higher priority items make better choices for u.
  27. The "A" in LIATE stands for:Algebraic (polynomials). A = Algebraic functions (polynomials like x, x², x³). These are often chosen as u when combined with exponentials or trig.
  28. After applying IBP to ∫x eˣ dx: u=x, v=eˣ, we get xeˣ − ∫eˣ dx. The remaining integral ∫eˣ dx = ?. ∫eˣ dx = eˣ + C. So the full result is xeˣ − eˣ + C = eˣ(x−1) + C.