Concept:
• Order: The order of a differential equation is the order of the highest derivative present in the equation.
• Degree: The degree is the power of the highest order derivative, provided the equation is a polynomial in its derivatives.
Step 1: Expand the given differential equation
The given equation is:
\[ \frac{d}{dx}(y')^3 + (y')^3 = 1 \]
We need to perform the differentiation in the first term with respect to \( x \).
Using the chain rule:
\[ \frac{d}{dx} \left( \frac{dy}{dx} \right)^3 = 3 \left( \frac{dy}{dx} \right)^2 \cdot \frac{d}{dx} \left( \frac{dy}{dx} \right) \]
\[ = 3(y')^2 \cdot y'' \]
Step 2: Rewrite the full equation
Substituting the derivative back into the original equation:
\[ 3(y')^2 y'' + (y')^3 = 1 \]
Or in standard notation:
\[ 3 \left( \frac{dy}{dx} \right)^2 \left( \frac{d^2y}{dx^2} \right) + \left( \frac{dy}{dx} \right)^3 = 1 \]
Step 3: Identify the order and degree
The highest derivative present in the equation is the second derivative, \( y'' \) or \( \frac{d^2y}{dx^2} \).
Therefore, the order is 2.
The highest order derivative term is \( 3(y')^2 y'' \).
The exponent (power) of this term \( (y'') \) is 1.
Therefore, the degree is 1.