kill(all)$

load(ntrig)$
load(atrig1)$

asinh1(u):=log(sqrt(u^2+1)+u);

van=facebook.com/LearningCalculus$

eq:'diff(y,x) = sqrt((1+y^2)/(1+x^2));

solution:ode2(eq,y,x);

asinh1(y) = asinh1(x)+%c;