How do you convert ##y = x## into polar form?

I found: ##tan(theta)=1##

Consider the following diagram:

We can see that the relationships between rectangular and are: ##r=sqrt(x^2+y^2)## ##theta=arctan(y/x)## and: ##x=rcos(theta)## ##y=rsin(theta)##

Given our expression: ##y=x## you have: ##cancel(r)sin(theta)=cancel(r)cos(theta)## and write: ##tan(theta)=1##