Determine order and degree(if defined)of differential equation \(\frac{d^4y}{dx^4}\)+sin(y''')=0
\(\frac{d^4y}{dx^4}\)+sin(y''')=0
⇒y''' '+sin(y''')=0
The highest order derivative present in the differential equations is y''' '.Therefore, its order is four.
The given differential equation is not a polynomial equation in its derivatives. Hence, its degree is not defined.
A racing track is built around an elliptical ground whose equation is given by \[ 9x^2 + 16y^2 = 144 \] The width of the track is \(3\) m as shown. Based on the given information answer the following: 
(i) Express \(y\) as a function of \(x\) from the given equation of ellipse.
(ii) Integrate the function obtained in (i) with respect to \(x\).
(iii)(a) Find the area of the region enclosed within the elliptical ground excluding the track using integration.
OR
(iii)(b) Write the coordinates of the points \(P\) and \(Q\) where the outer edge of the track cuts \(x\)-axis and \(y\)-axis in first quadrant and find the area of triangle formed by points \(P,O,Q\).
The equation that helps us to identify the type and complexity of the differential equation is the order and degree of a differential equation.
The highest order of the derivative that appears in the differential equation is the order of a differential equation.

The highest power of the highest order derivative that appears in a differential equation is the degree of a differential equation. Its degree is always a positive integer.
For examples: