ln(x) is the companion of nobody. Get inspired to make sense to a project & close the clasroom. In mathematics, ln(0) is defined -∞ or may be defined as complex. X_Y does not plot mixed discrete/scalar. To make sense to this plot, you must discretise both traces and slide the X direction for ln(X).
Smath QuickPlot is scalar on the cavas. Thus, it will start plotting on the fist computable value of the canvas. The cavas is 363 pixel range. The first ln(x) computed for plotting is ln(1/363)= -5.89. This technique is applicable to detect the first computed value of any other function(s)