Sin sin 45°+60°- cos cos 60°

sin sin 45° + 60° - cos cos 60° = 1/2 * 1/2 + √3/2 - √3/2 * 1/2 = 1/4 + √3/2 - √3/4 = 1/4 + 2√3/4 - √3/4 = (1 + √3)/4