CONJUGATE GRADIENT METHOD. Let f(X,Y)=25​X2+Y2−3XY−Y−7 (i) Write f(X,Y) in the form f(X,Y)=21​(X,Y)t2(X,Y)−(X,Y)t(B1​,B2​)+C. (ii) Use the conjugate gradient algorithm to construct a vector d1 using Xˉ0=(0,0)t (iii) Prove that d1 is 2-conjugate with ∇f(Xˉ0)