Q2A: Let f(x,y): See the attachment

Q 1 : Let flu.y) = In(atx + y 1) Determine an equation of the tangent plane to the Surface Z = f( x,y) at the point (1, - 1, 0). 2) Determine a First-order Taylor polynomial generated by f at the point ( 1, - 1), then approximate the value f ( 4/5 , - 4/5 )