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Find Vf at the given point. f(x,y,z)=e"* sinz+ (y+ 8) cos 'x, 0,0, Vf k 0,0 . F (Type an exact answer, using radicals as needed.)Find the derivative of the function at Po in the direction of A. f(x,y.z) =5 e * cos (yz), Po (0,0,0), A=i+ 2j+ 3k (DAf) (0,0,0) = (Type an exact answer, using radicals as needed.)In what directions is the derivative of f(x,y) = xy + y- at P(2,7) equal to zero? Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. u= (Simplify your answer. Use a comma to separate answers as needed. Type your answer in terms of i and j.) O B. There is no solution.The plane z = Ax + By + C is to be "fitted" to the following points (Xk,yk.Zk): (1, - 1,0), (- 1,0, - 1), (- 1,1, - 1), 4 (0, - 1,0). Find the values of A, B, and C that minimize 2 (AX* + Byk + C-ZK) the sum of the squares of the k = 1 deviations. A= B = C = (Simplify your answers.)Use Taylor's formula to find a quadratic approximation of f(x,y) = 3 cos x cosy at the origin. Estimate the error in the approximation if |x| = 0.16 and ly| = 0.07. Find a quadratic approximation of f(x,y) = 3 cos x cosy at the origin. f(x,y) = 3- 2 (3 x- + 3y?) The maximum error if |x|