" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
= sin² x - cos² x
= sin²x - (1 - sin² x)
= sin²x - 1 + sin² x
= 2 sin² x - 1
= -(1 - 2 sin²x)
= - cos 2x