Question 3 - A-Level Maths

Show that \(x ^ { 2 } = 1 - 2 y\) can be written in the form \(x ^ { 2 } + y ^ { 2 } = ( 1 - y ) ^ { 2 }\).
A curve has cartesian equation \(x ^ { 2 } = 1 - 2 y\). Find its polar equation in the form \(r = \mathrm { f } ( \theta )\), given that \(r > 0\).