Q.
Let $f(x) = \sqrt{x - 1} + \sqrt{x + 24 - 10\sqrt{x - 1}},\ 1 \leq x \leq 26$ be real valued function, then $f^{'}(x)$ for $1 < x < 26$ is
A) 0
B) $\frac{1}{\sqrt{x - 1}}$
C) $2\sqrt{x - 1} - 5$
D) None of these
Explanation
(a)
From Rolle’s theorem in given interval, [1,26], $f(1) = (26) = 5$ function satisfy all the condition of Rolle’s theorem, therefore in [1,26], at least, there is one point for which $f^{'}(x) = 0$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.