Q. If $f(x) = \left\{ \begin{array}{r} e^{\cos x}\sin{x,} \\ 2, \end{array}\ \begin{matrix} |x| \leq 2 \\ otherwise \end{matrix}, \right.\$ then $\int_{- 2}^{3}{f(x)dx}$ is equal to

A) 0
B) 1
C) 2
D) 3
Explanation

(c)
$\int_{- 2}^{3}{f(x)dx = \int_{- 2}^{2}{f(x)dx +}\int_{2}^{3}{f(x)dx}}$
$= \int_{- 2}^{2}{e^{\cos x}\sin{x\ dx +}}\int_{2}^{3}{2\ dx}$
Function of Ist integral is an odd function, therefore the value of Ist integral is zero.
$\therefore\ \ \int_{- 2}^{3}{f(x)dx = 0 + 2\lbrack x\rbrack_{2}^{3}}$
$= 0 + 2(3 - 2) = 2$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.

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