Relations and Functions — Class 12 Maths Solution

exemplar objective MCQ NCERT Exemp.Q.47,Page 16
Question

If $f:R \to R$ be given by $f(x) = \tan x$, then ${f^{ - 1}}(1)$ is

  • (a) None of these ✓ Correct
  • (b) $\frac{\pi }{4}$
  • (c) $\left\{ {n\pi + \frac{\pi }{4}:n \in Z} \right\}$
  • (d) Does not exist
Step-by-step Solution
Correct answer: option (a)

It is given that,, $f(x) = \tan x$

Let $y = \tan x \Rightarrow x = {\tan ^{ - 1}}y$

$\Rightarrow$ ${f^{ - 1}}(x) = {\tan ^{ - 1}}x \Rightarrow {f^{ - 1}}(1) = {\tan ^{ - 1}}1$

$\Rightarrow$ $= {\tan ^{ - 1}}\tan \frac{\pi }{4} = \frac{\pi }{4}$

NCERT & Exemplar solution for CBSE Class 12 Mathematics, Relations and Functions. Curated by Sachin Sharma. Free for all students.