Addition formula for Cosine
cos (u + v) = cos (u) cos (v) - sin (u) sin (v)
Subtraction Formula for Cosine
cos (u - v) = cos (u) cos (v) + sin (u) sin (v)
Addition Formula for Sine
sin (u + v) = sin (u) cos (v) + cos (u) sin (v)
Subtraction Formula for Sine
sin (u - v) = sin (u) cos (v) - cos (u) sin (v)
Addition Formula for Tangent
tan (u + v) = [tan (u) + tan (v)] / [1 - tan (u) tan (v)]
Subtraction Formula for Tangent
tan (u - v) = [tan (u) - tan (v)] / [1 + tan (u) tan (v)]