The forced wave equation is, using subscripts to denote differentiation with respect to the subscript variable, \[ u_{t t}=c^{2} u_{x x}+F(t, x), \] where \( F(t, x) \) is the forcing term, \( u(t, x) \) is displacement at position \( x \) and time \( t \) and \( c \) is the wave speed. You are to develop a Matlab code to solve this equation numerically, using the method of lines, for various wave speeds \( c \), on \( 0 \leq x \leq 1 \), with boundary conditions \( u(t, 0)=u(t, 1)=0 \), initial conditions \( u(0, x)=u_{t}(0, x)=0 \), and \( F(x, t)=3 \operatorname{sign}\left(x-\frac{1}{2}\right) \sin (\pi t) \). (a) Using a centred space discretisation, give the system of ODEs and associated initial conditions you will solve along with any algebraic equations. (b) Explain/show the matrix system that will be solved.