" The value of "2cos x-cos3x-cos5x" is equal to "

The value of 2 cos x - cos 3x - cos 5x is

If cos ecx=(2)/(sqrt(3)) and cot x=(-1)/(sqrt(3))x in[0,2 pi], then the value of cos x+cos2x+cos3x is equal to

The value of (cos3x)/(2cos2x-1) is equal to

If 3sin x+4 cos x=2, then the value of 3 cos x -4 sin x is equal to:

The minimum value of 2cos x-3cos^(2)x+5 is

int(cos5x+cos4x)/(1-2cos3x)dx " is equal to "

if cos x=-4/5 , where x in [ 0,pi] then the value of cos (x/2) is equal to