Solving the Initial-Value Problem y'''=(x^2)(e^x), y(0)=1, y'(0)=-2, y(0)=3

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In summary, the conversation is about solving an initial-value problem involving a third-order derivative and given initial conditions. The solution is obtained using integration by parts and the final answer is checked for accuracy.
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Math10
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Homework Statement


Solve the initial-value problem y'''=(x^2)(e^x), y(0)=1, y'(0)=-2, y"(0)=3.


Homework Equations


Here's the work:

I did integration by parts and got y"=(x^2)(e^x)+(2x)(e^x)-2e^x+C
C=5
y"=(x^2)(e^x)+2x(e^x)-2e^x+5
y'=(x^2)(e^x)+2x(e^x)-2e^x+2x(e^x)-2e^x-2e^x+5x+C
C=4
y'=(x^2)(e^x)+2x(e^x)-2e^x+2x(e^x)-2e^x-2e^x+5x+4
and I did the same thing to get y. But I got y=(x^2+6x-12)e^x+(5/2)x^2+4x+13 as the answer. Is this answer right?


The Attempt at a Solution

 
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  • #2
Math10 said:

Homework Statement


Solve the initial-value problem y'''=(x^2)(e^x), y(0)=1, y'(0)=-2, y"(0)=3.


Homework Equations


Here's the work:

I did integration by parts and got y"=(x^2)(e^x)+(2x)(e^x)-2e^x+C
C=5
y"=(x^2)(e^x)+2x(e^x)-2e^x+5
y'=(x^2)(e^x)+2x(e^x)-2e^x+2x(e^x)-2e^x-2e^x+5x+C
C=4
y'=(x^2)(e^x)+2x(e^x)-2e^x+2x(e^x)-2e^x-2e^x+5x+4
and I did the same thing to get y. But I got y=(x^2+6x-12)e^x+(5/2)x^2+4x+13 as the answer. Is this answer right?

I don't know, but you can easily check it yourself. Does your ##y'''=x^2e^x##? Is ##y(0)=1##? Is ##y'(0) = -2##? Is ##y''(0)=3##? If so, you have your answer.
 
  • #3
Thank you.
 

Related to Solving the Initial-Value Problem y'''=(x^2)(e^x), y(0)=1, y'(0)=-2, y(0)=3

1. What is an initial-value problem?

An initial-value problem is a type of mathematical problem that involves finding the solution to a differential equation based on specified initial conditions. This means that the problem provides information about the value of the unknown function at a particular starting point, or initial value.

2. What is the process for solving an initial-value problem?

The process for solving an initial-value problem involves first identifying the differential equation and its initial conditions. Then, using mathematical techniques such as separation of variables or integration, the solution to the equation is found. Finally, the initial conditions are used to determine the specific values of the unknown function at the starting point.

3. What are the applications of initial-value problems?

Initial-value problems are commonly used in various fields of science and engineering, such as physics, chemistry, and biology. They can be used to model and predict the behavior of physical systems, chemical reactions, and biological processes.

4. What are the limitations of initial-value problems?

One limitation of initial-value problems is that they assume the differential equations describing the system are accurate and complete. However, in many real-world situations, there may be additional factors that are not accounted for in the equations, leading to potential errors in the predicted behavior.

5. Are there any alternative methods for solving initial-value problems?

Yes, in addition to traditional mathematical methods, there are also numerical methods for solving initial-value problems. These involve using algorithms and computer programs to approximate the solution to the differential equation. While they may not provide an exact solution, they are often more practical for complex systems and can still provide valuable insights and predictions.

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