Differentiability Practice
Take timed practice tests on Differentiability for JEE Main and JEE Advanced with session-wise drills, score review, and explanation-led revision.
Take timed practice tests on Differentiability for JEE Main and JEE Advanced with session-wise drills, score review, and explanation-led revision.
Six 20-question timed sessions plus one 60-question module test. Each question is original and calibrated from the uploaded material pattern without copying PDF wording.
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1. The derivative f'(x) is defined as:
Explanation: First principles definition of the derivative: f'(x) = lim(h→0) [f(x+h)−f(x)]/h, provided this limit exists.
2. d/dx (xⁿ) equals:
Explanation: Power rule: d/dx(xⁿ) = nxⁿ⁻¹. For example: d/dx(x³) = 3x².
3. d/dx [f(g(x))] equals:
Explanation: Chain rule: if y = f(g(x)), then dy/dx = f'(g(x)) × g'(x). Example: d/dx(sin x²) = cos(x²) × 2x.
4. d/dx [u × v] equals:
Explanation: Product rule: d/dx(uv) = u'v + uv'. Example: d/dx(x sin x) = sin x + x cos x.
5. To differentiate y = xˢⁱⁿ ˣ, we use:
Explanation: For y = f(x)^g(x), take ln: ln y = g(x) ln f(x). Differentiate both sides: y'/y = g'(x) ln f(x) + g(x) f'(x)/f(x). Multiply by y for y'.
6. For x² + y² = r², dy/dx equals:
Explanation: Implicit differentiation: differentiate both sides w.r.t. x: 2x + 2y(dy/dx) = 0 → dy/dx = −x/y.
7. If y = sin x, then d²y/dx² is:
Explanation: y' = cos x. y'' = d/dx(cos x) = −sin x.
8. f(x) = |x| is not differentiable at x = 0 because:
Explanation: Left derivative: lim(h→0⁻) (|h|−0)/h = −1. Right derivative: lim(h→0⁺) h/h = +1. LHD ≠ RHD → not differentiable at x = 0 (though f is continuous there).
9. The derivative of sin⁻¹x is:
Explanation: d/dx(sin⁻¹x) = 1/√(1−x²) for |x|
10. If x = t², y = t³, then dy/dx is:
Explanation: dy/dx = (dy/dt)/(dx/dt) = (3t²)/(2t) = 3t/2.
11. If y = tan⁻¹(2x/(1−x²)), then dy/dx for |x| < 1 is:
Explanation: Recognize: 2x/(1−x²) = tan(2θ) when x = tan θ. So y = tan⁻¹(tan 2θ) = 2θ = 2tan⁻¹x. dy/dx = 2/(1+x²).
12. d/dx(ln x) equals:
Explanation: d/dx(ln x) = 1/x for x > 0. More generally, d/dx(ln|x|) = 1/x.
13. d/dx(eˣ sin x) equals:
Explanation: Product rule: (eˣ)'sin x + eˣ(sin x)' = eˣ sin x + eˣ cos x = eˣ(sin x + cos x). Options A and B are identical expressions.
14. The nth derivative of eˣ is:
Explanation: Differentiating eˣ any number of times gives eˣ. Dⁿeˣ = eˣ for all positive integers n.