MATH 6A Lecture 9: Lecture 9
Document Summary
Definition: is differentiable at a point if: exists at for all and. The matrix of the partial derivatives of at satisfies. Note: is the product of an matrix with the vector , viewed as an matrix. The equation of the straight line that is tangent to at. The fact that the limit goes to 0 says that is closely approximated by near. In 2 variables, , the expression simplifies to: It is the equation of the plane tangent to the graph of at the point. Example: find the equation of the plane tangent to at the point.
