# How do you use inverse trig functions to find angles?

Mar 14, 2018
1. Know that arccos, arcsec functions are restricted to quad 1 and 2
2. Know that arctan, arccot, arcsin, arccsc are restricted to quad 1 and 4
3. And when you go to quadrant 4 with arctan, arccot, arcsin, arccsc, use negative angles

Examples
1.$\arcsin \left(1\right) = \frac{\pi}{2}$
2. $\arctan \left(- 1\right) = - \frac{\pi}{4}$
3. $a r c \sec \left(\frac{1}{2}\right) = D N E$
4. $a r c \csc \left(- \sqrt{2}\right) = - \frac{\pi}{4}$