Chapter 8.3, Problem 23P

Find the orthogonal trajectories of the family of curves $y=-e^{x^2}$ erf $x+C{e}^{x^2}.$

Hint: See Chapter 11, equation (9.1) for definition of erf $x$, and Chapter 4, Section 12, for differentiation of an integral. Solve for $x$ in terms of y.