Practice Inverse Trigonometric Functions in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Functions that reverse the trigonometric functions: given a ratio, they return the corresponding angle. \arcsin, \arccos, and \arctan are the inverses of \sin, \cos, and \tan on restricted domains.

Regular trig functions answer: 'Given an angle, what's the ratio?' Inverse trig functions answer the reverse: 'Given a ratio, what's the angle?' Since \sin and \cos are many-to-one (many angles give the same ratio), we must restrict their domains to make the inverse a proper function. Think of it like this: if you know the slope of a ramp is 0.5, \arcsin(0.5) = 30ยฐ tells you the angle.

Example 1

easy
Evaluate \arcsin\!\left(\frac{1}{2}\right), \arccos\!\left(-\frac{\sqrt{2}}{2}\right), and \arctan(1). State the range of each inverse trig function.

Example 2

hard
Simplify \sin(\arccos(x)) for x\in[-1,1] without trigonometric functions in the final answer.

Example 3

easy
A right triangle has opposite side 5 and hypotenuse 13. Find the angle \theta opposite the side of length 5 using \arcsin.

Example 4

medium
Solve 2\sin(x)-1=0 on [0,2\pi] using \arcsin, and explain why there are two solutions.