A method for finding the optimal control of linear singular systems with a
quadratic cost functional using Legendre series is discussed. The state var
iable, state rate, and the control vector are expanded in the shifted Legen
dre series with unknown coefficients. The relation between the coefficients
of the state rate with state Variable is provided and the necessary condit
ion of optimality is derived as a system of algebraic equations. A numerica
l example is included to demonstrate the validity and the applicability of
the technique.