\[ -y'(x)^2+y(x) y''(x)+1=0 \] ✓ Mathematica : cpu = 0.15393 (sec), leaf count = 44
\[\left \{\left \{y(x)\to -e^{-c_1} \sinh \left (e^{c_1} (x+c_2)\right )\right \},\left \{y(x)\to e^{-c_1} \sinh \left (e^{c_1} (x+c_2)\right )\right \}\right \}\] ✓ Maple : cpu = 2.933 (sec), leaf count = 86
\[ \left \{ y \left ( x \right ) ={\frac {1}{2} \left ( -{\it \_C1}\, \left ( {{\rm e}^{{\frac {x}{{\it \_C1}}}}} \right ) ^{2} \left ( {{\rm e}^{{\frac {{\it \_C2}}{{\it \_C1}}}}} \right ) ^{2}+{\it \_C1} \right ) \left ( {{\rm e}^{{\frac {{\it \_C2}}{{\it \_C1}}}}} \right ) ^{-1} \left ( {{\rm e}^{{\frac {x}{{\it \_C1}}}}} \right ) ^{-1}},y \left ( x \right ) ={\frac {1}{2} \left ( {\it \_C1}\, \left ( {{\rm e}^{{\frac {x}{{\it \_C1}}}}} \right ) ^{2} \left ( {{\rm e}^{{\frac {{\it \_C2}}{{\it \_C1}}}}} \right ) ^{2}-{\it \_C1} \right ) \left ( {{\rm e}^{{\frac {{\it \_C2}}{{\it \_C1}}}}} \right ) ^{-1} \left ( {{\rm e}^{{\frac {x}{{\it \_C1}}}}} \right ) ^{-1}} \right \} \]