Q. If the primitive of $\frac{1}{f(x)}$ is equal to $\log{\left\{ f(x) \right\}^{2} + c,\ then\ f(x)}$ is

A) $x + d$
B) $\frac{x}{2} + d$
C) $\frac{x^{2}}{2} + d$
D) $x^{2} + d$
Explanation

(b)
Given that, $\int_{}^{}{\frac{1}{f(x)}dx = \log{\left\{ f(x) \right\}^{2} + c}}$
$\Rightarrow \ \frac{1}{f(x)} = \frac{1}{\left\{ f(x) \right\}^{2}}2f(x)f^{'}(x)$
$\Rightarrow f^{'}(x) = \frac{1}{2}$
$\Rightarrow f(x) = \frac{x}{2} + d$
(where $d$ is a integration constant)

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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