Prove this trig identity csc^4-csc^2=cot^4 cot^2

Csc = 1/sin

csc^4 -csc^2 = cot^4 *cot^2

cot = cos/sin 

1/sin^4 - 1/sin^2 = (cos/sin)^4 *(cos/sin)^2

(1 - sin^2)
= (cos^4)/(sin^4) *(cos^2)/(sin^2)
sin^4

sin^2 +cos^2 = 1 so from this result 1-sin^2 = cos^2

cos^2       cos^6
=  cross multiply 
sin^4        sin^6

sin^6 *cos^2 = sin^4 *cos^6    divide both sides by sin^4*cos^2

sin^2 = cos^4