Evaluate the following expressions. Your answer must be an exact angle in radians and in the interval $\displaystyle {\left[-{\frac{{\pi}}{{{2}}}},{\frac{{\pi}}{{{2}}}}\right]}$. For example, type pi/6 for $\displaystyle \frac{\pi}{{6}}$.

$\displaystyle {{\tan}^{{-{1}}}{\left({0}\right)}}=$ Preview Question 6 Part 1 of 3  

$\displaystyle {{\tan}^{{-{1}}}{\left(-{1}\right)}}=$ Preview Question 6 Part 2 of 3  

$\displaystyle {{\tan}^{{-{1}}}{\left(-\sqrt{{{3}}}\right)}}=$ Preview Question 6 Part 3 of 3