The definition of the error function also defines an "error term" E(x, y). 7 xyz at the point (6, 1, 31). Round your answer 6 Find E(x, y) for the function x³ + y³ = coefficients to at least 4 decimal places. Calculate Duf(3, 1, — 5) in the direction of 7 = i + 37 - 3k for the function = : 5x² + 5xy + 2y² − 2x − 5yz — 5z² + 4xz. f(x, y, z) Round your answer to four decimal places.