The Sine Addition Formulas - Concept

Concept Concept (1)

Starting with the cofunction identities, the sine addition formula is derived by applying the cosine difference formula. There are two main differences from the cosine formula: (1) the sine addition formula adds both terms, where the cosine addition formula subtracts and the subtraction formula adds; and (2) the sine formulas have sin-sin and cos-cos. Both formulas find values for angles.

Sample Sample Problems (3)

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The Sine Addition Formulas - Problem 1
Problem 1
How to use the sine of a sum formula to simplify an expression or to find the sine of an angle.
The Sine Addition Formulas - Problem 2
Problem 2
How to derive the sine of a difference formula and use it to find the sine of an angle.
The Sine Addition Formulas - Problem 3
Problem 3
How to evaluate sin(a - b) and sin(a + b) when you know only cos(a) and sin(b).