`5(tan^(2)x-cos^(2)x) = 2cos2x +9` , then the value of cos4x is:

6tan^(2)x-2cos^(2)x=cos2x if cos2x=

If cot^(4)x-cot^(2)x=1 , then the value of cos^(4)x+cos^(2)x is ________

If (sin^(2)x-2cos^(2)x+1)/(sin^(2)x+2cos^(2)x-1)=4 , then the value of 2 tan^(2)x is

Let cos(2 tan^(-1) x)=1/2 then the value of x is

If tan x+tan^(2)x+tan^(8)x=1, then the value of 2cos^(6)x-2cos^(4)+cos^(2)x equals to

If cos^(2)x+cos^(4)x=1 , then find the value of tan^(2)x+tan^(4)x .

If (sin x + cos x)/(sin x - cos x) = (6)/(5) , then the value of (tan^(2) x + 1)/(tan^(2) x-1) is :

" If "sin^(2)x+sin x cos x-6cos^(2)x=0" and "-(pi)/(2)ltxlt0," then value of "cos2x" is " -3/5 3/5 -4/5 4/5