Like everyone else with a computer and too much free time, I regularly check in at a few websites which have nothing to do with news or public affairs or world hunger or professional advancement or the rigors of the writing life. No, they amuse me. Entertain me. Once in a while, shed unexpected light on a neglected dark corner. This Is Indexed is one of them; below, this morning’s offering.

The abcissa needs a reference point/value
OK. I really meant abscissa
From context, I infer max/min values for X at 1/75. As no specific points are indicated, and the graph is crudely hand-drawn, I assume the curve is parabolic, though experience suggests the right side is too steep and the left side should allow for a negative value of X.
Sorry, that obviously (I hope) should read min/max, or 75/1.