Question

-1 (\frac{ \sqrt{3} }{2}) " alt="sin ^-1 (\frac{ \sqrt{3} }{2}) " align="absmiddle" class="latex-formula">
$cos^-1( -\frac{\sqrt{3} }2} )$

$tan^-1(-1)$

$cos^-1 (cos \frac{4 \pi }{3}})$

Answer 1

#1 

the answer is 60.

#2

The answer is 150.

#3

The answer is -45

#4

The answer is 4.18879 ≈ 4.2