[[_2nd_order, _missing_x]]
Book solution method
TO DO
Mathematica ✗
cpu = 600.002 (sec), leaf count = 0 , timed out
$Aborted
Maple ✓
cpu = 5.438 (sec), leaf count = 532
DSolve[y[x]*(1 + a^2 - 2*a^2*y[x]^2) + b*Sqrt[(1 - y[x]^2)*(1 - a^2*y[x]^2)]*y'[x]^2 + (1 - y[x]^2)*(1 - a^2*y[x]^2)*y''[x] == 0,y[x],x]
Mathematica raw output
$Aborted
Maple raw input
dsolve((1-y(x)^2)*(1-a^2*y(x)^2)*diff(diff(y(x),x),x)+b*((1-y(x)^2)*(1-a^2*y(x)^2))^(1/2)*diff(y(x),x)^2+(1+a^2-2*a^2*y(x)^2)*y(x) = 0, y(x),'implicit')
Maple raw output
Intat(exp(2*b*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)^(1/2),_g))/(exp(2*b*Int(1/(_g^4*a
^2-_g^2*a^2-_g^2+1)^(1/2),_g))*(4*a^2*Int(exp(b*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)
^(1/2),_g))^2*_g^3/(1+_g^4*a^2+(-a^2-1)*_g^2),_g)-2*a^2*Int(exp(b*Int(1/(_g^4*a^
2-_g^2*a^2-_g^2+1)^(1/2),_g))^2*_g/(1+_g^4*a^2+(-a^2-1)*_g^2),_g)+_C1-2*Int(exp(
b*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)^(1/2),_g))^2*_g/(1+_g^4*a^2+(-a^2-1)*_g^2),_g
)))^(1/2),_g = y(x))-x-_C2 = 0, Intat(-exp(2*b*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)^
(1/2),_g))/(exp(2*b*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)^(1/2),_g))*(4*a^2*Int(exp(b
*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)^(1/2),_g))^2*_g^3/(1+_g^4*a^2+(-a^2-1)*_g^2),_
g)-2*a^2*Int(exp(b*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)^(1/2),_g))^2*_g/(1+_g^4*a^2+
(-a^2-1)*_g^2),_g)+_C1-2*Int(exp(b*Int(1/(_g^4*a^2-_g^2*a^2-_g^2+1)^(1/2),_g))^2
*_g/(1+_g^4*a^2+(-a^2-1)*_g^2),_g)))^(1/2),_g = y(x))-x-_C2 = 0