I have a few things im stuck on.. <.< I might be able to answere one through the example of others..

1) Find the polar equation for the curve x^2 + y^2 = 4

2)Find the equation in x and y for the curve with parametric equations x=(cost) -2 and y= (sin t) +3 for 0 is less or = to t and t is less or = to pie

3) Sketch the graph of the plar equation r=2-cos feta

4) Find an equation in x and y that has the same graph as r=2cos feta - 4sin feta