5.4
Sum and Difference Identities for Sine and Tangent

__Sine of a Sum or
Difference__

_{}

__Tangent of a Sum or
Difference__

_{}

__Example__

Find
the **exact** value of each expression

_{}

Write
each function as an expression involving functions of θ.

_{}

_{}

**Finding Function
Values and the Quadrant of A + B**

__Example__

Suppose
that A* *and B are angles in standard
position, with

_{}

Find
each of the following:

a) _{} b) _{}

c) the quadrant of *A – B*

**Verifying An Identity using Sum and Difference Identities**

__Example__

Verify
that the equation is an identity.

_{}