Answer:
1
Step-by-step explanation:
[tex]cot^4x-cot^2x=1\\cot^4x=1+cot^2x\\cot^4x=cosec^2x\\ cos^4xsin^2x=sin^4x\\cos^4x=\frac{sin^4x}{sin^2x}\\cos^4x=sin^2x[/tex]------- (1)
Putting the value of [tex]cos^4x[/tex] in the equation:
[tex]cos^4x+cos^2x\\sin ^2x +cos^2x\\1[/tex] (Using the identity [tex]cos^2x +sin^2x=1)[/tex]
