A one-dimensional quartic oscillator has V = cx4, where c is a constant. Devise a variation function

Question:

A one-dimensional quartic oscillator has V = cx4, where c is a constant. Devise a variation function with a parameter for this problem, and find the optimum value of the parameter to minimize the variational integral and estimate the ground-state energy in terms of c. Compare with the Numerov-method ground-state energy found in Prob. 4.32.