This past week was exam week so we really didn't have much time to learn anything new. On Friday however we learned section 10-1.In this chapter we are not allowed to use calculators. The purpose of this section is to find exact values and to simplify, you must know the trig chart in order to learn this section.

You only need to know to Formulas:
Alpha and Beta come straight out of the trig chart

Cos(alpha +/- beta) = cosalpha cosbeta -/+ sinalpha sinbeta

Sin(alpha +/- beta) = sinalpha cosbeta +/- cosalpha sinbeta


Example:
Find the exact value of sine 150
a). Look on your trig chart and see if there are any two degrees that add up to 150. 90 and 60 add up to give you 150.
b). They want sine so plug into your sine formula. Sin( 90 + 60) = sin90 cos60 + cos90 sin60
c). Plug in from your trig chart. (1) (1/2) + (1) (square root 3/2)
d). Your final answer is 2