sir plz help!!!

find the general solution of sin2 4x + cos2x = 2 sin4x. cos4x.

1 Answers

62
Lokesh Verma ·

(sin4x-cos4x)2 + cos2x - cos8x = 0
cos2x - cos8x >=0!
so this implies that

cos2x - cos8x =0
cosx=0 or 1 or -1
is equivalent to cosx=0 or sinx=0

and sin4x-cos4x=0

when cosx=0 it will be a soln here!

when sinx=0.. tihs will not be zero..

so the solution will be when cosx=0

so x = (2n+1) pi/2

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