Given function F(x,y)=6x^3+3x^2y-y^3-6x a) The directional derivative in the point (-1,2) in the direction of the origin b) In what direction does the F increase most in the point (-1,2)? How large is the direction- driven in this direction c) Locate the stationary/critical points of the function d) Classify the desktop/critical points e) f) Find a tangent plane formula for the function at the point (1,1,2) Use the tanget plane formula to approximate the value of the function at he point (X,Y)= (0.9,1.1) the difference between approximate and accurate value