Hey I am not sure how to find the second coordinate of these polar coordinates.

a) Find polar coordinates (r,θ) of the point (4, -4), wherer> 0 and 0 ≤θ≤ 2π.

So

I tried doing

θ=

θ=

θ=

θ=

But this is incorrect?

Forr< 0 and 0 ≤θ≤ 2π.

How do I find theta?