Solve(y-x 1)-(y x 2)dx=0?
Problem:
Solve the given differential equation: (y - x^2)dx + (y - x^2)dy = 0.
Solution:
To solve the given differential equation, we will use the method of exact differential equations. A differential equation is said to be exact if it can be written in the form M(x, y)dx + N(x, y)dy = 0, where M and N are functions of both x and y, and their partial derivatives with respect to y and x, respectively, are equal: ∂M/∂y = ∂N/∂x.
Step 1: Identifying M and N
In the given differential equation, (y - x^2)dx + (y - x^2)dy = 0, we can identify M = y - x^2 and N = y - x^2.
Step 2: Checking for Exactness
To check if the equation is exact, we need to verify if ∂M/∂y = ∂N/∂x.
∂M/∂y = 1
∂N/∂x = -2x
Since ∂M/∂y ≠ ∂N/∂x, the equation is not exact.
Step 3: Introducing the Integrating Factor
To make the equation exact, we need to find an integrating factor, denoted by μ(x, y), which is a function that multiplies both M and N to make the equation exact. The integrating factor is given by the formula:
μ(x, y) = e^(∫(∂M/∂x - ∂N/∂y)dx)
In this case, μ(x, y) = e^(∫(-2x - 1)dx)
Step 4: Finding the Integrating Factor
To find the integrating factor, we need to compute the integral in the formula for μ(x, y).
∫(-2x - 1)dx = -x^2 - x + C
Therefore, μ(x, y) = e^(-x^2 - x + C) = e^(-x^2 - x)e^C = Ce^(-x^2 - x)
Step 5: Multiplying the Equation by the Integrating Factor
Now, we multiply both sides of the given differential equation by the integrating factor μ(x, y):
Ce^(-x^2 - x)(y - x^2)dx + Ce^(-x^2 - x)(y - x^2)dy = 0
Simplifying this equation gives us:
Cy(e^(-x^2 - x)dx + e^(-x^2 - x)dy) - Cx^2(e^(-x^2 - x)dx + e^(-x^2 - x)dy) = 0
Step 6: Simplifying and Integrating
Now, we can see that the equation is exact, and we can write it as:
d(F(x, y)) = 0
where F(x, y) = Cy - Cx^2.
Integrating both sides, we get:
F(x,