# How do you evaluate  sin(arctan(3/4))?

$\pm \frac{3}{5}$
Let $a = a r c \tan \left(\frac{3}{4}\right)$
Then, $\tan a = \frac{3}{4} > 0$. a iis in the 1st quadrant or in the 3rd.
So, the given expression $\sin a = \pm \frac{3}{5}$.