Cos (pi\3)-cos (pi\3-h) разложить на множители. )

Cos (pi/3) - cos(pi/3-h) = cos(pi/3) - cos(pi/3)cos h - sin(pi/3)sin h = 1/2 - 1/2cos h - √3/2sin h = 1/2(1 - cos h - √3sin h) = 1/2(1-2sin(pi/6+h))