eh the directional derivative of xy at the point (2, 1) has the value 2. 29. Find all points at which the direction of fastest change of the function f(x, y)= x2 + y - 2x -4y is i + 30. Near a buoy, the

W A person's Body Mass Index is I H² where W is the body weight (in kilograms) and H is the body height (in meters). A child has weight W = 39 kg and height H = 1.3 m. Use the linear approximation to estimate the change in I if (W, H) changes to (40, 1.31). (Use decimal notation. Give your answer to three decimal places.) ΔΙ~

Integrate function

The definition of the error function also defines an "error term" E(x, y). Find E(x, y) for the function f(x, y) = 3x² + 5y at the point (7,-7). Hint: See the definition of Differentiation in the textbook (link to textbook) Submit Question D