f(x_1, x_2, x_3)= x_1^2+ 5 x_2^2 + 25 x_3^2 + x_1 + x_2- x_3
The starting point is (1, 1, 1).
Perform three steps using 
 1)  steepest descent
  2) conjugate gradient
  3)quasi-Newton 
 methods. (Notice that the first step is identical in all methods). Using Newton method, compute the minimum. 
Discuss convergence of the methods used.