1. Tardigrade
  2. Question
  3. Mathematics
  4. If f (x)=cos2x+sec2x, then

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. If $f \left(x\right)=cos^{2}x+sec^{2}x$, then

Trigonometric Functions

Solution:

Given, $f(x) = cos^2x + sec^2x$
Using $A.M. \ge G.M.$
$\therefore \frac{cos^{2}\,x+sec^{2}\,x}{2} \ge\sqrt{cos^{2}\,x\times sec^{2}\,x}$
$\Rightarrow cos^{2}x+sec^{2}x \ge 2$
$\therefore f \left(x\right)\ge 2$