If f (Sin & nbsp; x) = 3-cos & nbsp; 2x, then f (COS & nbsp; x) = () A. 3-cos 2xB. 3-sin 2xC. 3+cos 2xD. 3+sin 2x

If f (Sin & nbsp; x) = 3-cos & nbsp; 2x, then f (COS & nbsp; x) = () A. 3-cos 2xB. 3-sin 2xC. 3+cos 2xD. 3+sin 2x

If f (SiNx) = 3-cos2x = 3 - (1-2sin2x) = 3-1 + 2sin2x = 2sin2x + 2, then f (cosx) = 2cos2x + 2 = 2cos2x-1 + 3 = 3 + cos2x