Find all solutions on the interval $\displaystyle {\left[{0}^{\circ},{360}^{\circ}\right)}$. Use exact values. 

 $\displaystyle {8}{{\sin}^{{2}}{x}}-{4}{\cos{{x}}}-{4}={0}$ 

Separate multiple solutions with a comma. If there are no solutions please enter, "no solution" exactly.