The slope of is1.

You'll need to find the slope of the segment between(a, b)and(b, a).

Since the slopes are negative reciprocals of each other, the lines are perpendicular.

is the linear identity function. this means thexandyvalues are identical.

The midpoint between (a, b)and(b, a)can be found using the midpoint formula:

Since bothxandyvalues of the midpoint are identical, then the midpoint has to lie on the identity function