Question

The order of the differential equation

$\frac{d^2}{{\mathrm{dx}}^2}\left(\frac{\mathrm{dy}}{\mathrm{dx}}\right)+2\frac{d^{2}y}{{\mathrm{dx}}^2}+\frac{\mathrm{dy}}{\mathrm{dx}}=\mathrm{sinx}$ is .

Answer 1

The given differential equation can be simplified as $\frac{d^{3}y}{{\mathrm{dx}}^3}+2\frac{d^{2}y}{{\mathrm{dx}}^2}+\frac{\mathrm{dy}}{\mathrm{dx}}=\mathrm{sinx}$.
Order of a DE is the highest order derivative present in it. Thus the answer is 3.