Use LHpitals rule lim [f(x)/g(x)] x 0 = lim [df(x)dx/dg(x)/dx] x 0 to show that

Use L’Hôpital’s rule lim [f(x)/g(x)]_{x → 0} = lim [df(x)dx/dg(x)/dx]_{x → 0} to show that the expression derived for Pf in part b of Example problem 1.1 hane the correct limit as y → 0.