Graph of y=|f(x)|: reflect the portion below x-axis to above. Graph of y=f(|x|): keep the right half (x>=0), reflect it to the left (making the graph symmetric about y-axis). Graph of |y|=f(x): keep the portion where f(x)>=0, reflect it below x-axis. These transformations are tested in graph-matching MCQs and help visualize solution counts.