1. ## Trigonometric Equation

$2cotx+sec^2x=0$

$xe[0,2\pi]$

2. ## Re :

Originally Posted by cdx
$2cotx+sec^2x=0$

$xe[0,2\pi]$

$\frac{2}{tanx}+(1+tan^2x)=0$ , multiply the whole thing by tan x

$tan^3x+tanx+2=0$

Let tan x = y

$y^3+y+2=0$ ... Can u continue from here ?

3. Thanks, I forgot about the identity

$
sec^2x = 1 + tan^2x
$