a. Find the linear approximation for the following function at the given point. b. Use part (a) to estimate the given function value. f(x.y) = 8x - by + 3xy; (3,5); estimate f(2.0,5.06) a. L(x.y) =Find the equation of the plane tangent to the following surface at the given points. x2 + v2 - z- - 101 =0; (6,0,4) and ( - 9, - 6.4) The equation of the tangent plane at (8,0.4) is =0