Verify the following identities:
a. cos x (tan^2 x + 1) = sec x
_________ = 1
tan x csc x
c. (sin^2 x - sin^4 x)cos x = cos^3 x sin ^2 x
Trigonometric identities are verified. The solution is detailed and well presented. The response received a rating of "5/5" from the student who originally posted the question.