Solve the equations below exactly. Give your answers in radians, and find all possible values for $t$ in the interval $0 \leq t \leq 2 \pi$. If there is more than one answer, enter your solutions in a comma separated list.

(a) $\displaystyle \sin{(t)} = \frac{\sqrt{2}}{2}$ when $t =$

(b) $\displaystyle \cos{(t)} = - \frac{\sqrt{2}}{2}$ when $t =$

(c) $\displaystyle \tan{(t)} = - \frac{1}{\sqrt{3}}$ when $t =$