# The degree of the differential equation $\bigg(\large\frac{d^2y}{dx^2}\bigg)^3+\bigg(\frac{dy}{dx}\bigg)^2$$+\sin\bigg(\large\frac{dy}{dx}\bigg)$$+1=0\; is$

$(A)\;3\qquad (B)\;2\qquad(C)\;1\qquad(D)\;not \; defined$

Toolbox:
• The highest order derivative present in the differential equation determines the order of the equation.The power to which this derivative is raised determines the degree of the equation.
Step 1:
The highest order derivative present in the differential equation is $\large\frac{d^2y}{dx^2}$.Hence its order is 2.
Step 2:
It is not a polynomial equation in its derivatives.So its degree is not defined.
Step 3:
The correct option is $D$.