23. Prove that cosê A-sino A = cos 2A 1-
Attachments:
Answers
Answered by
0
Hey dear ✌....
Here's your answer....
(cos2a)3 – (sin2a)3=
(cos2a – sin2a )(cos4a + sin4a + cos2a*sin2a)
= (cos2a)(1-2 cos2a*sin2a + cos2a*sin2a)
=(cos2a)(1 –cos2a*sin2a )
= (cos2a)(1 –4cos2a*sin2a/4)
= cos2a(1-1/4sin22a)
Hence proved!
Follow me ✌....
Similar questions