I was given the following equation $\frac{dy}{dx}=\sqrt{y-4}$ and was asked to solve it and find a family of solutions. I've solved the equation so that $y=\frac{x^2+16}{4}+c$ or $y=\frac{x^2}{4}+4+c$. I've now been asked if I can find a second singular solution not contained in a family. Can someone explain to me what exactly this means? I'm not even sure how to begin going about solving this question, as I'm not sure I understand it.
Much appreciated!