Question

Prove That :
____________

Answer 1

\[4\cos 2A+\cos4A=8\sin ^{4}A\]

Answer 2

apply formuls cos2A = 1-2(sinA)^2

Answer 3

and cos(4A) = cos(2(2A))

Answer 4

@Lumenaire ... :):)

Answer 5

@Eyad now solve n tell us u able to prove?

Answer 6

@vedic :Ty i solved it ,something was confusing me but i did it ty :)

Answer 7

btw i need u in another question can u help ?

Answer 8

yeah sure...

Answer 9

@vedic: Have you tried proving it? If yes, how?

Answer 10

This does not hold http://www.wolframalpha.com/input/?i=4+Cos+%5B2+A%5D+%2B+Cos+%5B4+A%5D+%3D+8+%28Sin+%5BA%5D%29%5E4

Answer 11

@FoolForMath .. wait fr few mints i will solve n tell..

Answer 12

@FoolForMath i am not able to solve it ryt nw.... bt i will try again n get back to u...

Answer 13

This is a wrong question.

Answer 14

@Eyad .. how u proved it?