Thread: arctan question

$\displaystyle -\frac{\pi}{4}=arctan(\frac{\frac{-2L}{3}}{R})\\$
why it equals
$\displaystyle \frac{\frac{-2L}{3}}{R}=-1$
?

Originally Posted by transgalactic

$\displaystyle -\frac{\pi}{4}=arctan(\frac{\frac{-2L}{3}}{R})\\$
why it equals
$\displaystyle \frac{\frac{-2L}{3}}{R}=-1$
?

By taking "tan" for the both sides of the first equation.

I'm not sure what you are asking.

$\displaystyle \arctan(x)=-\pi/4$ has just one solution, which is $\displaystyle x=-1$.