User Guide

Figure 4.7: Directional Derivative Tutor
To compute a symbolic value for the directional derivative, use the Stu-
dent[MultivariateCalculus][DirectionalDerivative] command. The first
list of numbers specifies the point at which to compute the derivative. The
second list of numbers specifies the direction in which to compute the deriv-
ative.
For example, at the point [1, 2], the gradient of points in the direction
[2, 4], which is the direction of greatest increase. The directional derivative
in the orthogonal direction [-2, 1] is zero.
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160 • 4 Mathematical Computations