How do you verify tan^2x-tan^2x*sin^2x=sin^2xtan2xtan2xsin2x=sin2x?

2 Answers
Apr 8, 2018

Please see below.

Explanation:

tan^2x-tan^2x*sin^2xtan2xtan2xsin2x

= tan^2x(1-sin^2x)tan2x(1sin2x)

= tan^2xcos^2xtan2xcos2x

= sin^2x/cos^2x*cos^2xsin2xcos2xcos2x

= sin^2xsin2x

Apr 8, 2018

"see explanation"see explanation

Explanation:

"using the "color(blue)"trigonometric identities"using the trigonometric identities

•color(white)(x)tanx=sinx/cosxxtanx=sinxcosx

•color(white)(x)sin^2x+cos^2x=1xsin2x+cos2x=1

"consider the left side"consider the left side

"take out a common factor "tan^2xtake out a common factor tan2x

tan^2x(1-sin^2x)tan2x(1sin2x)

=sin^2x/cancel(cos^2x)xxcancel(cos^2x)

=sin^2x=" right side "rArr"verified"