Express the cartesian coordinates (0, 4) as polar coordinates.

The question is asking we convert from (x, y) coordinate to (r, theta) coordinates.

So (0, 4) to (r, theta)

x = 0 and y = 4.

r = âš (x^2 + y^2)

r = âš (0^2 + 4^2)

r = âš (0 + 16)

r = 4

Also theta = tan^ (-1) (x/y) = tan^ (-1) (0/4) = 0

So theta = 0

Hence the (r, theta) coordinate is (4, 0)