How do I prove that sin^2x + tan^2xsin^2x = tan^2x ?
2 Answers
Sep 20, 2015
Use
Explanation:
By definition:
tan x = sin x / cos x
and by Pythagoras:
sin^2 x + cos^2 x = 1
So:
tan^2 x = sin^2 x / cos^2 x = sin^2 x / cos^2 x(cos^2 x + sin^2 x)
= (sin^2x cos^2x)/cos^2 x + (sin^2 x sin^2 x) / cos^2 x
= sin^2 x + sin^2 x tan^2 x
Sep 20, 2015
Using the rules: