how do I prove that tan x (cot x + tan x) = sec^2 x thank you May 16 | L from Jacksonville, NC | 1 Answer | 0 Votes Mark favorite Subscribe Comment
tan(x)[cot(x) + tan(x)] = sec^{2}(x) Identity: cot(x) = 1/tan(x) tan(x)[(1/tan(x)) + tan(x)] = sec^{2}(x) tan(x)/tan(x) + tan^{2}(x) = sec^{2}(x) 1 + tan^{2}(x) = sec^{2}(x) which is a Pythagorean identity. May 16 | Philip P. Comment