Can someone explain to me how this has multiple answers? I really don't understand! When I did it I only got the first answer. Please help! I will mark brainliest, but I will also report anyone who gives an improper answer.

[tex]in \: firt \: quadrant \\ sin \frac{\pi}{4} = \frac{ \sqrt{2} }{2} \\ in \: second \: quadrant \\ sin \frac{3\pi}{4} = \frac{ \sqrt{2} }{2} \\ in \: third \: quadrant \: \\ sin \frac{5\pi}{4} = \frac{ - \sqrt{2} }{2} \\ in \: forth \: quadrant \\ sin \frac{7\pi}{4} = - \frac { \sqrt{ 2} }{2} \\ in \: this \: way \: it \: has \: multiple \: soution[/tex]