Question 236357
Remember that *[Tex \LARGE \theta=tan^{-1}\left(\frac{y}{x}\right)]



*[Tex \LARGE \theta=tan^{-1}\left(\frac{y}{x}\right)] ... Start with the given equation.



*[Tex \LARGE 45=tan^{-1}\left(\frac{y}{x}\right)] ... Plug in *[Tex \LARGE \theta=45]



*[Tex \LARGE tan(45)=tan\left(tan^{-1}\left(\frac{y}{x}\right)\right)] ... Take the tangent of both sides.



*[Tex \LARGE 1=tan\left(tan^{-1}\left(\frac{y}{x}\right)\right)] ... Evaluate the tangent of 45 degrees to get 1.



*[Tex \LARGE 1=\frac{y}{x}]  ... Evaluate the tangent of the arctangent of {{{y/x}}} to get {{{y/x}}}. In other words, the two cancel out.



*[Tex \LARGE x=y] ... Multiply both sides by x.



So the rectangular equation is {{{y=x}}}.