Question

( 2 cdot cos 2 x=2left(2 cos ^{2} x-1right) )
( x+cos 2 x=2 cos ^{2} x-4 )
( x=2 cos ^{2} x )
( frac{cos x=pm 1}{x}=n pi, n in I )

# The general solution of the equation 2cos2x = 3.2cos2x - 4 is (A) x = 2n1, nel (B) X = n ,n el (C) x=nt/4, nel (D) X = n/2, nel

Solution