Question 8

Mathematics Continuous function Medium

What is the value of \( a \) for which \( f(x) \) is continuous? \[ f(x) = \begin{cases} \sin x, & \text{if } x \leq \frac{\pi}{2} \\ a x, & \text{if } x > \frac{\pi}{2} \end{cases} \]

(A) \( \pi \)
(B) \( \pi / 2 \)
(C) \( 2 / \pi \)
(D) 0
View Dynamic Solution & Explanation
Correct Solution: Option C

Step-by-step Solution:

For continuity at \( x = \frac{\pi}{2} \),

LHL: \( \lim_{x \to \frac{\pi}{2}^-} f(x) = \sin \frac{\pi}{2} = 1 \)

RHL: \( \lim_{x \to \frac{\pi}{2}^+} f(x) = a \cdot \frac{\pi}{2} \)

For continuity, LHL = RHL:
\( 1 = a \cdot \frac{\pi}{2} \)

Solving for \( a \):
\( a = \frac{2}{\pi} \)