final!!!!!!!

The law of sines

sin A
a = sin B
b = sin C
c
This can also be interpreted as three equations:

sin B
b = sin C
c , sin A
a = sin C
c , and sin A
a = sin B
b

The law of cosines

c2 = a2 + b2 – 2ab cos C
There are two other versions of the law of cosines,

a2 = b2 + c2 – 2bc cos A and b2 = a2 + c2 – 2ac cos B.

n a circle whose radius is 10 cm, a central angle θ intercepts an arc of 8 cm.

a) What is the radian measure of that angle?
Answer. According to the definition:
θ = s
r = 8
10 = .8
b) At that same central angle θ, what is the arc length if the radius is
b) 5 cm?

Answer. For a given central angle, the ratio of arc to radius is the same. 5 is half of 10. Therefore the arc length will be half of 8: 4cm.
Converting radians and degrees
Convert 200° into radian measure:
200° (Π/180°) = 200/180Π radians or 3.49 radians
Convert 1.4 radians into degrees: 1.4 (180°/Π) = 80.2 °

http://www.math.uakron.edu/~tprice/Trig/Graphs.pdf Great powerpoint on sine and cosines waves.