Answer:
(a) [tex]\theta=\tan^{-1}(-0.890)[/tex]
[tex]\implies \theta=-41.66908262 \pm 180 \textdegree n[/tex]
[tex]\implies \theta=138.3309174..., 318.3309174...[/tex]
[tex]\implies \theta=138\textdegree, 318\textdegree[/tex]
(b) [tex]\theta=\cos^{-1}\left(\dfrac{\sqrt{3} }{2}\right)[/tex]
[tex]\implies \theta=30 \textdegree \pm360 \textdegree n, 330 \textdegree \pm360 \textdegree n[/tex]
[tex]\implies \theta=30 \textdegree , 330 \textdegree[/tex]
(c) [tex]\theta=\sin^{-1}\left(\dfrac{1 }{2}\right)[/tex]
[tex]\implies \theta=30 \textdegree \pm360 \textdegree n, 150 \textdegree \pm360 \textdegree n[/tex]
[tex]\implies \theta=30 \textdegree , 150 \textdegree[/tex]
