find an angle between 0 and 2pi that is coterminal with the angle given by -77pi/5
thanks! much appreciated
oops, yeah sry, $\displaystyle \frac{3\pi}{5} $ is right.
$\displaystyle \frac{-77\pi}{5} = -15\pi -\frac{2\pi}{5} $ (You can check this).
Now $\displaystyle -15\pi $ is "being at the same place" as just $\displaystyle \pi $ .
So being at pi, $\displaystyle \frac{5\pi}{5} - \frac{2\pi}{5} = \frac{3\pi}{5} $