To illustrate the variational method, use the ground state, normalized Harmonic Oscillator Wavefunction:
ψ(x) = (α/π)^(1/4) * e^(-αx^2/2)
a. Using this as the "guess" for the wavefunction, find the expectation value of the energy and find an expression for α which minimizes this energy.
b. Show that it is in fact the same final energy expression as that given by solving the Schrödinger Equation. Just look up the equation, don't solve the Schrödinger Equation.