Question

The letters x and y represent rectangular coordinates. Write the following equation using polar coordinates (r, θ).
Given equation: y=x
I chose: r=cosθ
oobleck
no, r = cosθ is a circle with radius 1/2 and center at (1/2,0)
y = x
Is just a line with a slope of 1, right?
r sinθ = r cosθ
sinθ = cosθ
tanθ = 1

don't forget your algebra 1.