1. Inverse Trig = Solve for the Angle
Inverse Trig Functions
Inverse Trig = Solve for the Angle

2. INVERSE vs. RECIPROCAL
Its important not to confuse an INVERSE trig function with a RECIPROCAL trig function.
The reciprocal of SINE is COSECANT: (sin x ) -1 = csc x
The inverse of SINE is ARCSIN: sin -1 x = arcsin x
The notation is very important - be careful !!

3. Evaluating INVERSE Trigs
Evaluating an inverse trig means finding the ANGLE that gives us the stated ratio. For example, to evaluate arcsin 0.5, (read “the arcsine of 0.5”) we must ask ourselves “for what angle does sin = 0.5 ? “
Answer: 30° or π/6 radians

4. How Many Answers are Right?
There are other angles for which the sine of that angle = For example
sin 30° = 0.5
sin 150° = 0.5
sin 390° = 0.5
The way we could handle this is to give a general solution, that is written in a way such that all possible solutions are included in it.

5. Summary
When evaluating a trig function for a given angle, there is ONE ANSWER. Remember all the rules for evaluating trig functions: reference & coterminal angles, positive & negative quadrants, etc.
When evaluating an inverse trig function, there can be INFINITE ANSWERS.