Question

Which angle is not coterminal to 4pi/3 radians? -120 degrees,960 degrees,-540 degrees,or -840 degrees?

Answer 1

well, convert the radian unit to degrees, and then check which one isn't coterminal to it :)

\(\begin{array}{llll}
degrees&radians
\\\hline\\
180&\pi \\
x&\frac{4\pi }{3}
\end{array}\implies \cfrac{180}{x}=\cfrac{\pi }{\frac{4\pi }{3}}\)