Trigonometry Formulas and Properties

cos 𝜋𝜋 2 −𝜃𝜃 = sin 𝜃𝜃 sec 𝜋𝜋 2 −𝜃𝜃 = csc 𝜃𝜃 cot 𝜋𝜋 2 −𝜃𝜃 = tan𝜃𝜃. Product to Sum Formulas: sin 𝛼𝛼sin𝛽𝛽= 1 2 [cos(𝛼𝛼−𝛽𝛽) −cos(𝛼𝛼+ 𝛽𝛽)] cos 𝛼𝛼cos𝛽𝛽= 1 2 [cos(𝛼𝛼−𝛽𝛽) + cos(𝛼𝛼+ 𝛽𝛽)] sin𝛼𝛼cos𝛽𝛽= 1 2 ................
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