Visualizing the Directional Derivative
Grab the blue point at the tail of the arrow move it around; move the dot at the head of the arrow to change which direction we're taking the directional derivative in.
The red line is the line whose slope computes ; the green line is the line whose slope computes .
The black line is the line whose slope computes .
Use the toggle switches to change visibility:
graphvisible turns the graph of f on and off.
xtangentvisible turns the tangent line whose slope is on and off.
ytangentvisible turns the tangent line whose slope is on and off.
planevisible turns the tangent plane on and off.
Vslicevisible turns the slice which we use to compute on and off.
normalvisible turns the normal on and off.
Enter your own function in place of the default .