How do you graph and find the vertex for #abs y=x#?

1 Answer
May 26, 2015

The vertex of a function containing a modulus is typically at the point where the enclosed expression changes sign.

In the case of #abs(y) = x# the vertex is at #(0,0)#

When #y >= 0# the equation boils down to #y = x# - the equation of a #45^o# line with slope #1#.

When #y < 0# the equation boils down to #-y = x#, that is #y = -x# - the equation of a line with slope #-1#.

graph{x=abs(y) [-10, 10, -5, 5]}