- (a) Solve the equation \(4 x ^ { 2 } + 12 x = 0\).
You are given that \(\mathrm { f } ( x ) = 4 x ^ { 2 } + 12 x + c\), where \(c\) is a constant.
(b) Given that \(\mathrm { f } ( x ) = 0\) has equal roots, find the value of \(c\) and hence solve \(\mathrm { f } ( x ) = 0\).