Inverse trig ratios, including sin-1, cos-1, and tan-1, are used to solve for missing angle measures. When given a decimal value for sin, cos, or tan, the corresponding inverse trig function is used to find the angle measure to the nearest degree. When given a triangle, the appropriate trig ratio is set up and the inverse function is then used to find the measure of the indicated angle to the nearest degree.

2. Inverse trig ratios are used to
solve for missing angle measures.
They include:
sin-1
cos-1
tan-1

3. When given a decimal value:
Find each angle measure to the
nearest degree.
sinθ = 0.7193
cosθ = 0.3907
tanθ = 0.6009

4. When given a triangle:
Set up the appropriate ratio,
then use the inverse.
Find the measure of the
indicated angle to the nearest
degree.

5. Find the measure of the indicated
angle to the nearest degree.

6. Find the measure of the indicated
angle to the nearest degree.
1. tanθ = 1.6003
2.