Find the solution to the initial value problem

In summary, the solution to the initial value problem is y = (2e^2x + c)/e^x, where c is a constant determined by the initial condition y(0)=3.
  • #1
mad_monkey_j
33
0

Homework Statement


Find the solution to the initial value problem
dy/dx - y = e^3x
y(0) = 3

Homework Equations


e^∫p(x)

The Attempt at a Solution


Do I treat p(x) = -1?
I(x) = e^∫-1 = e^-x
e^-x(dy/dx) - ye^-x = e^3x . e^-x
e^-x(dy/dx) - e^-x . y = e^2x
e^-x . y = ∫e^2x
y = (2e^2x + c)/(e^-x)
y = C+2e^3x?
 
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  • #2
mad_monkey_j said:

Homework Statement


Find the solution to the initial value problem
dy/dx - y = e^3x
y(0) = 3

Homework Equations


e^∫p(x)

The Attempt at a Solution


Do I treat p(x) = -1?
I(x) = e^∫-1 = e^-x
e^-x(dy/dx) - ye^-x = e^3x . e^-x
e^-x(dy/dx) - e^-x . y = e^2x
e^-x . y = ∫e^2x
y = (2e^2x + c)/(e^-x)
y = C+2e^3x?
Yes, in this case p(x)=-1. However, you're answer isn't correct as it doesn't satisfy the initial value problem. You have made a little slit in the second to last line of your working.
 

FAQ: Find the solution to the initial value problem

1. What is an initial value problem?

An initial value problem is a type of differential equation that involves finding a function that satisfies both a given differential equation and a set of initial conditions. These initial conditions specify the value of the function at a certain point or points.

2. How do you solve an initial value problem?

An initial value problem can be solved by using various methods such as separation of variables, substitution, and integrating factors. These methods involve manipulating the given differential equation to isolate the dependent and independent variables, and then using the initial conditions to determine any constants of integration.

3. What makes an initial value problem different from other types of differential equations?

An initial value problem is unique because it requires finding a specific function that satisfies both the differential equation and the given initial conditions. This means that there is only one solution to the problem, rather than a general solution that can be found for other types of differential equations.

4. Can an initial value problem have multiple solutions?

No, an initial value problem can only have one unique solution. This is because the initial conditions are used to determine any constants of integration, leaving no room for multiple solutions.

5. How do you check if a solution to an initial value problem is correct?

To check if a solution to an initial value problem is correct, you can plug the solution into the given differential equation and see if it satisfies both the equation and the initial conditions. It is also helpful to graph the solution to visualize if it aligns with the initial conditions.

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