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Question #41472

Difficulty: 8/10 | 🟢 Free

The Question

Let f(x)=e[x]∫0xsgn(sin⁡(πt))dtf(x) = e^{[x]} \int_{0}^{x} \text{sgn}(\sin(\pi t)) dt, where [x][x] denotes the greatest integer less than or equal to xx. Evaluate the definite integral ∫0202f′(x)dx\int_{0}^{202} f'(x) dx, where the integration is performed over the points of differentiability of f(x)f(x).

Options

  • A.

    00

  • B.

    1−e2021+e\frac{1 - e^{202}}{1 + e}

  • C.

    e202−1e−1\frac{e^{202} - 1}{e - 1}

  • D.

    1+e2021+e\frac{1 + e^{202}}{1 + e}

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Specialist

Targeted practice for niche, high-difficulty concepts that frequently appear in JEE Advanced exams.

Concepts Behind This Question

The Sign-Consistency Principle|Newton-Leibniz Formula with variable limits|Greatest Integer Function Traps

Why This Question Is Tricky

Common Mistakes

This question tests the student's ability to recognize the breakdown of the Fundamental Theorem of Calculus (Newton-Leibniz) when a function contains jump discontinuities induced by the Greatest Integer Function.

Students incorrectly assume that ∫0202f′(x)dx=f(202)−f(0)=0\int_{0}^{202} f'(x) dx = f(202) - f(0) = 0.

To solve correctly, they must partition the integral at integer points, apply the Sign-Consistency principle to evaluate the piecewise constant sign of sin⁡(πt)\sin(\pi t), and sum the resulting geometric progression.

Quick Facts About This Question

Question Information

SubjectMathematics
ChapterApplication of Integrals - Class 12
ConceptThe Sign-Consistency Principle
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree