Does #sin^2theta-cos^2theta=1-2sin^2theta#?

2 Answers
May 12, 2018

#"No"#
#"Almost :"#
#sin^2(theta) - cos^2(theta) = 2 sin^2(theta) - 1#

Explanation:

#sin^2(theta) + cos^2(theta) = 1#

#=> sin^2(theta) - cos^2(theta)#
#= sin^2(theta) - (1 - sin^2(theta))#
#= 2 sin^2(theta) - 1#

May 12, 2018

No that would be equal to #2sin^2theta-1#

Explanation:

Since #cos^2theta=1-sin^2theta#
Putting the value #cos^2theta# in original equation we get
#2sin^2theta-1#