The homogeneous differential equation
y′′−4y′+4y=0
is given. A family of exponential functions is proposed in the form y(x)=ekx, where k is a real constant.
(a) Determine y′(x) and y′′(x) for the proposed function.
(b) Substitute these expressions into the differential equation and find all real values of k for which y(x)=ekx satisfies the equation.
(c) For each distinct value of k obtained in part (b), write an independent solution and state the dimension of the solution space for the differential equation.