Evaluate the following expressions. Give an exact answer in radians.

(a) sin⁡−1(22)=\displaystyle {{\sin}^{{-{1}}}{\left({\frac{{\sqrt{{{2}}}}}{{{2}}}}\right)}}=  

(b) sin⁡−1(0)=\displaystyle {{\sin}^{{-{1}}}{\left({0}\right)}}=  

(c) sin⁡−1(−1)=\displaystyle {{\sin}^{{-{1}}}{\left(-{1}\right)}}=  

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