[tex]arctan(x)=y[/tex]
this function is the inverse function of tan...
[tex]arctan(x)=tan^{-1}(x)[/tex]
then...
[tex]x=tan(y)[/tex]
in this case
[tex]arctan(\frac{3}{5})=K[/tex]
[tex]\frac{3}{5}=tan(K)[/tex]
[tex]\boxed{\boxed{tan(K)=\frac{3}{5}}}[/tex]
