Functions with two arguments can be visualized in three-dimensional plots. Getting this on paper or into a PDF, is a bit more challenging. We need a projection, a view point, or angle, there’s a depth which means parts should be hidden and others in the front.
We will use the pgfplots package to plot f(x,y) = sin(x)*sin(y).
The code, and more, is explained in the LaTeX Cookbook, Chapter 10, Advanced Mathematics, Plotting in three dimensions.
Edit and compile if you like:% Plotting in three dimensions% Author: Stefan Kottwitz% https://www.packtpub.com/hardware-and-creative/latex-cookbook\documentclass[border=10pt]{standalone}\usepackage{pgfplots}\begin{document}\begin{tikzpicture}\begin{axis} [title = {$f(x,y) = \sin(x)\sin(y)$},xtick = {0,90,...,360},ytick = {90,180,...,360},xlabel = $x$, ylabel = $y$,ticklabel style = {font = \scriptsize},grid]\addplot3 [surf, domain=0:360, samples=60]{ sin(x)*sin(y) };\end{axis}\end{tikzpicture}\end{document}
Open in Overleaf: 3d-plot.tex