Question

Demuestra cada identidad:
A) sen x/tan x = cos x
B) sen x - sec x = tan x
C) cos²x (tan²x+1) = 1
D) sen x/cos x - tan x/ctg x = 1

Answer 1

(sen x)/(tan x) = cos x
(sen x)/1/(sen x)/(cos x) = cos x
(sen x . cos x)/(sen x) = cos x
cos x = cos x