## How do you separate variables with differential equations?

Step 1 Separate the variables by moving all the y terms to one side of the equation and all the x terms to the other side:

- Multiply both sides by dx:dy = (1/y) dx. Multiply both sides by y: y dy = dx.
- Put the integral sign in front:∫ y dy = ∫ dx. Integrate each side: (y2)/2 = x + C.
- Multiply both sides by 2: y2 = 2(x + C)

### What is variable separable differential equation?

Separable differential equations are a special type of differential equations where the variables involved can be separated to find the solution of the equation. Separable differential equations can be written in the form dy/dx = f(x) g(y), where x and y are the variables and are explicitly separated from each other.

**How do you solve a variable separable differential equation?**

The method for solving separable equations can therefore be summarized as follows: Separate the variables and integrate.

- Example 1: Solve the equation 2 y dy = ( x 2 + 1) dx.
- Example 2: Solve the equation.
- Example 3: Solve the IVP.
- Example 4: Find all solutions of the differential equation ( x 2 – 1) y 3 dx + x 2 dy = 0.

**What is the difference between differential equation and ordinary differential equation?**

Partial differential equations are differential equations that contain functions with multiple variables and their partial derivatives, while ordinary differential equations are differential equation that contain functions with just one variable and their derivatives.

## How do you test for the exactness of a differential equation?

Exact Differential Equation Integrating Factor

- If the differential equation P (x, y) dx + Q (x, y) dy = 0 is not exact, it is possible to make it exact by multiplying using a relevant factor u(x, y) which is known as integrating factor for the given differential equation.
- Consider an example,
- 2ydx + x dy = 0.

### Which differential equation is not separable?

y = y sin(x − y) It is not separable. The solutions of y sin(x−y) = 0 are y = 0 and x−y = nπ for any integer n. The solution y = x−nπ is non-constant, therefore the equation cannot be separable.

**Why do we use ODEs?**

Differential equations are important because for many physical systems, one can, subject to suitable idealizations, formulate a differential equation that describes how the system changes in time.

**What is ordinary differential equation with example?**

An ordinary differential equation is an equation which is defined for one or more functions of one independent variable and its derivatives. It is abbreviated as ODE. y’=x+1 is an example of ODE.

## How do you solve an ordinary differential equation?

Solution: We multiply both sides of the ODE by dx, divide both sides by y2, and integrate: ∫y−2dy=∫7x3dx−y−1=74×4+Cy=−174×4+C. The general solution is y(x)=−174×4+C. Verify the solution: dydx=ddx(−174×4+C)=7×3(74×4+C)2. Given our solution for y, we know that y(x)2=(−174×4+C)2=1(74×4+C)2.