The level curves are the projections onto the [math]Oxy[/math] plane of the curves that we obtain by intersecting a function [math]z=f\left(x,y\right)[/math] with an horizontal plane given by the equation [math]z=k[/math].[br][br]As [math]k[/math] varies, we obtain a series of contours representing the points of the function that are at the same height: this visualization provides valuable insight into the behavior of [math]f\left(x\right)[/math].[br][br]Explore the level curves of various functions, such as [math]f\left(x,y\right)=xy[/math], [math]f\left(x,y\right)=\sqrt{x^2+y^2}[/math], or [math]f\left(x,y\right)=2x+5y-1[/math]. The SHOW/HIDE TRACE button allows you to toggle between viewing only the level curve corresponding to the current value of [math]k[/math] and displaying all the level curves within the selected range of [math]k[/math].[br][br]To rotate the 3D View, right-click and drag the mouse, or use standard touch gestures on mobile devices.