Q122 / 225 · JEE Main 2003 · Mathematics
The value of $\lim _{x \rightarrow 0} \frac{\int_0^{x^2} \sec ^2 t d t}{x \sin x}$ is
- A0
- B3
- C2
- Correct answerD1
Solution
$\operatorname{Lim}_{x \rightarrow 0} \frac{\frac{d}{d x} \int_0^{x^2} \sec ^2 t d t}{\frac{d}{d x}(x \sin x)}=\operatorname{Lim}_{x \rightarrow 0} \frac{\sec ^2 x^2 \cdot 2 x}{\sin x+x \cos x}$
(by L'Hospital rule)
$\operatorname{Lim}_{x \rightarrow 0} \frac{2 \sec ^2 x^2}{\left(\frac{\sin x}{x}+\cos x\right)}=\frac{2 \times 1}{1+1}=1$
Hence, the correct answer is option: 'D'.