Not middle school.

We're after the integral from 0 to B, less the right triangle OAB. So we need to find A and B.

The slope at 0 is



The normal has negative reciprocal slope, so m=-2 through (0,1/2)

The x intercept (when y=0) is B:


The right triangle area is

The integral is


The area we seek is the difference,

Answer: e/32