SOLUTION: find the value of sin4A and cos4A

Question 39252: find the value of sin4A and cos4A
Answer by fractalier(6550) (Show Source): You can put this solution on YOUR website!
Just posted sin 4a...but
cos 4a = cos 2(2a) =
cos^2 2a - sin^2 2a =
(cos^2 a - sin^2 a)^2 - (2 sin a cos a)^2 =
cos^4 a - 2 sin^2 a cos^2 a + sin^4 a - 4 sin^2 a cos^2 a =
cos^4 a + sin^4 a - 6 sin^2 a cos^2 a
Further manipulation is possible.
RELATED QUESTIONS
Prove that:... (answered by Edwin McCravy)

I have problem with this question: Find the value of sin4A (answered by fractalier)

proove that... (answered by Edwin McCravy)

Show the formula for... (answered by Alan3354)

Prove the following identities (i) cos2A + cos4A + cos6A + cos12A = 4cos3Acos4Acos5A (answered by Alan3354)

find the value of cos 600 and find the value of tan -30 thank u (answered by BC17)

Find the least value of {{{ 2x^2-4x+3 }}} and the corresponding value of... (answered by funmath)

Find the value of p and the value of q x^-6x+15 =... (answered by stanbon)

Find the value of the variable's 2x and... (answered by stanbon)