You can put this solution on YOUR website! Applying implicit differentiation on , we get
2yy' = cosx
another application of implicit differentiation yields
2[(y')^2 +yy"] = -sinx
===> (y')^2 +yy" = -(sinx)/2
===> (y')^2 +yy" + (sinx)/2 = 0, or
yy" + (y')^2 + (sinx)/2 = 0.
Since , it follows that a = 1/2, and b = -1/2.