A curve has equation \(y = x ^ { 2 } - 4\). Find the \(x\)-coordinates of the points on the curve where \(y = 21\).
The curve \(y = x ^ { 2 } - 4\) is translated by \(\binom { 2 } { 0 }\).
Write down an equation for the translated curve. You need not simplify your answer.