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Sum and Difference Formulas

Formulas for the sum and difference of two angles within a trigonometric function.

Mathematics.

Date Created:Friday January 26th, 2007 09:54 AM
Date Modified:Saturday August 02nd, 2008 12:26 PM

sin(α + β) = sinαcosβ + cosαsinβ

sin(α - β) = sinαcosβ - cosαsinβ


cos(α + β) = cosαcosβ - sinαsinβ

cos(α - β) = cosαcosβ + sinαsinβ

              tanα + tanβ
tan(α + β) = ______________

              1 - tanαtanβ


              tanα - tanβ
tan(α - β) = ______________

              1 + tanαtanβ