[_quadrature]
Book solution method
Missing Variables ODE, Independent variable missing, Solve for
Mathematica ✓
cpu = 0.0182653 (sec), leaf count = 23
Maple ✓
cpu = 0.037 (sec), leaf count = 31
DSolve[y'[x]^2 == 1 + y[x]^2,y[x],x]
Mathematica raw output
{{y[x] -> -Sinh[x - C[1]]}, {y[x] -> Sinh[x + C[1]]}}
Maple raw input
dsolve(diff(y(x),x)^2 = 1+y(x)^2, y(x),'implicit')
Maple raw output
1+y(x)^2 = 0, x-arcsinh(y(x))-_C1 = 0, x+arcsinh(y(x))-_C1 = 0