How to show that 1/2 (cos4x+cos2x) =cos3xcosx by using expansions of cos (3x+x) and cos (3x-x) - Quora
![The total number of solution of sin4x + cos4x = sinx cosx in [0, 2π] is equal to :-Correct answer is '2'. Can you explain this answer? | EduRev JEE Question The total number of solution of sin4x + cos4x = sinx cosx in [0, 2π] is equal to :-Correct answer is '2'. Can you explain this answer? | EduRev JEE Question](https://edurev.gumlet.io/ApplicationImages/Temp/321edae4-1453-4b0c-b090-c02adbc3961a_lg.jpg)
The total number of solution of sin4x + cos4x = sinx cosx in [0, 2π] is equal to :-Correct answer is '2'. Can you explain this answer? | EduRev JEE Question
![SOLVED: Express cos 4x in terms of cos X 0 A cos 3x - 3 sin 2x cos X 0 B. 3 sin x-4 sin X 0c: cos 4x - 6 sin SOLVED: Express cos 4x in terms of cos X 0 A cos 3x - 3 sin 2x cos X 0 B. 3 sin x-4 sin X 0c: cos 4x - 6 sin](https://cdn.numerade.com/ask_images/151db12d16ab4c5895bdb87f26d486f1.jpg)
SOLVED: Express cos 4x in terms of cos X 0 A cos 3x - 3 sin 2x cos X 0 B. 3 sin x-4 sin X 0c: cos 4x - 6 sin
![trigonometry - ($\cos^4x$)($\sin^2x$) in terms of first power of cosine - Mathematics Stack Exchange trigonometry - ($\cos^4x$)($\sin^2x$) in terms of first power of cosine - Mathematics Stack Exchange](https://i.stack.imgur.com/QSGsf.jpg)
trigonometry - ($\cos^4x$)($\sin^2x$) in terms of first power of cosine - Mathematics Stack Exchange
![Write Cos(4x) in Terms of Only Cos(x) or Verify the Identity Cos(4x)=8cos^4(x)-8cos^2(x)+1 - YouTube Write Cos(4x) in Terms of Only Cos(x) or Verify the Identity Cos(4x)=8cos^4(x)-8cos^2(x)+1 - YouTube](https://i.ytimg.com/vi/tzeHG-sDwlE/maxresdefault.jpg)