The constrained optimization worksheet (especially Part 2) guides you through the use of the Lagrange multipliers exploration tool. Not mentioned there however is a limitation of the Test point position slider. Although the test point can be moved to any position on the constraint curve using this slider, the slider does not enable you to move the test point around the curve repeatedly in the same direction. This limitation is overcome by the "hacked" color picker labelled Alternative test pt control. To move the test point with this control, first move your pointer over the colored bar to the right of the label to reveal a square color field. Then drag the small circular marker in this field clockwise or counterclockwise around the center of the field.