# Find all angles a in the interval [0degrees, 360 degrees] such that sin^2a-sina =0?

##### 1 Answer
May 23, 2018

$0 , {90}^{\circ} , {180}^{\circ} , {360}^{\circ}$

#### Explanation:

${\sin}^{2} a - \sin a = 0$
sin a(sin a - 1) = 0
Either factor should be zero -->
a. sin a = 0
Unit circle gives:
a = 0, $a = {180}^{\circ}$, and $a = {360}^{\circ}$
b. sin a - 1 = 0 --> sin a = 1
$a = {90}^{2}$