Below is the sign diagram for three linear expressions, denoted as [math]f(x)=a x-b[/math], [math]g(x)=c-d x[/math] and [math]h(x)=e x +f[/math] (colour coded), where [math]a,b,c,d,e,f[/math] are constant whose value you can change by operating with your mouse on the sliders. Points [math]F[/math], [math]G[/math] and [math]H[/math] indicate the points where each expression equals zero; continuous lines identify values of [math]x[/math] which render each expression positive, while the dashed lines refer to values of [math]x[/math] making an expression negative.]