2.1638   ODE No. 1638

ay(x)2+bsin(y(x))+y(x)=0

Mathematica : cpu = 5.98527 (sec), leaf count = 146

DSolve[b*Sin[y[x]] + a*Derivative[1][y][x]^2 + Derivative[2][y][x] == 0,y[x],x]
 
{{y(x)InverseFunction[1#14a2+14e2aK[1]c1a24bsin(K[1])a+e2aK[1]c1+2bcos(K[1])dK[1]&][x+c2]},{y(x)InverseFunction[1#14a2+14e2aK[2]c1a24bsin(K[2])a+e2aK[2]c1+2bcos(K[2])dK[2]&][x+c2]}}

Maple : cpu = 0.394 (sec), leaf count = 115

dsolve(diff(diff(y(x),x),x)+a*diff(y(x),x)^2+b*sin(y(x))=0,y(x))
 
y(x)4a2+116(a2+14)2c1e2_aa16(asin(_a)cos(_a)2)(a2+14)bd_axc2=0