In this video, learn how to find the scalar equation of a plane.

In this video, learn how to find the scalar equation of a line with a point and a vector.

In this video, learn howto find the sum of two vectors.

In this video, learn howto find the equation of a vector from two points. The two points given will become the initial and terminal points of the vector.

In this video, learn howto use Lagrange multipliers to find the extrema of a multivariable function that's defined by two variables, given only one constraint equation.

In this video, learn howto use Lagrange multipliers to find the extrema of a multivariable function that's defined by two variables, given only one constraint equation.

In this video, learn howto use the second derivative test to find local extrema (local maxima and local minima), and then compare local extrema to see which of them (if any) can be called global extrema (the global maximum and the global minimum).

You can use the second derivative test to find the extrema (maxima and minima) of a multivariable function.

In this video, learn howto use the gradient vector to find the equation of the tangent plane to a multivariable function at a particular point.

The gradient vector is a special component of the directional derivative. If we can identify the gradient vector, then we can see that the directional derivative in the direction of a unit vector u is the scalar projection of the gradient vector onto u.