1. Show that: a) Given x1,x2,x3, the formula to calculate the following approximation xr in the inverse quadratic interpolation method used to find a root of the function f(x) is: %xr=%%(x1f2f3)/((f1f2)(f1f3))+(x2f1f3)/((f2f1)(f2f3))+(x3f1f2)/((f3f1)(f3f2)); b) Given r,s,t, the formula to calculate the following approximation xc in the successive parabolic interpolation method used to find a critical point of the function f(x) is: %xc=((r+s)(fsfr)(tr)(ts)/((sr)(ftfs)(fsfr)(ts)))/2