Multivariable Calculus

How to solve

The gradient ∇f points in the direction of fastest increase and is perpendicular to the level curve through the point.

Steps

  1. Compute the partial derivatives.
  2. Evaluate them at P to get the gradient components.
  3. Check that the drawn vector is normal to the level curve.

Example

f = x² + y² at P = (1, 2).

  1. ∇f = ⟨2x, 2y⟩.
  2. ∇f(1, 2) = ⟨2, 4⟩.

Answer: 2 or 4 depending on the requested component

Loading drills…