cot x = cos x / sin x
tan x = sin x / cos x
(Find common denominators)
cosx/sinx * cosx/cosx = cos^2x/sinxcosx
sinx/cosx * sinx/sinx = sin^2x/sinxcosx
(Now we can combine them)
csc / (sin^2x+cos^2x / sinxcosx)
(Simplify)
csc*sinx*cosx / sin^2x+cos^2x
sin^2x + cos^2x = 1
csc*sinx*cosx / (1)
csc*sinx*cosx
csc = 1/sinx
1/sinx*sinx = 1
(1)*cosx = cosx