help with solving this equation

[donjt81]

Hi guys

I was solving a problem and I am stuck at solving this equation.

(sec x)^2 (tan x)^2 = 2
since we know that (sec x)^2 = 1 + (tan x)^2

[1 + (tan x)^2][(tan x)^2] = 2
(tan x)^2 + (tan x)^4 - 2 = 0

now what do i do...

thanks in advance.

[lotrgreengrapes7926]

Substitute "u = tan x" to get a quadratic.