Not sure what to do with this DE problem

  • Thread starter iRaid
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However, in this case, they may want you to get used to the idea of using the given solution in place of "y" and then making sure that the resulting equation is true. This is an important concept to understand as the equations get more complex. In summary, the problem is asking you to confirm that the given function, y = x^3 + 7, is a valid solution to the differential equation y' = 3x^2 by substituting it into the equation and making sure it is true. This is an important skill to develop for more complex equations in the future.
  • #1
iRaid
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Homework Statement


Verify by substitution that each given function is a solution of the given differential equation. Throughout these problems, primes denote derivatives with respect to x.
y'=3x2; y=x3+7


Homework Equations





The Attempt at a Solution


Well obviously I see that the derivative of y=x3+7 is just 3x2, but what does it mean by verifying by substitution? :confused:
 
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  • #2
iRaid said:

Homework Statement


Verify by substitution that each given function is a solution of the given differential equation. Throughout these problems, primes denote derivatives with respect to x.
y'=3x2; y=x3+7

Homework Equations


The Attempt at a Solution


Well obviously I see that the derivative of y=x3+7 is just 3x2, but what does it mean by verifying by substitution? :confused:

It means substitute [itex]y = x^3 + 7[/itex] into [itex]y' = 3x^2[/itex] to get [itex](x^3 + 7)' = 3x^2[/itex] and then confirm that the left hand side does in fact equal the right hand side. In this case it obviously does, so there's nothing more to do. Although I suppose you could expressly state that [itex](x^3 + 7)' = (x^3)' + (7)' = 3x^2 + 0 = 3x^2[/itex].
 
  • #3
Why do they make me even do this...?
 
  • #4
Usually, they don't anticipate the student having any problem verifying an equation given its solution.
 

1. What is a DE problem?

A DE problem, or differential equation problem, is a mathematical equation that involves an unknown function and its derivatives. It is commonly used to model physical processes or phenomena in various fields such as physics, engineering, and economics.

2. What are the types of DE problems?

There are two main types of DE problems: ordinary differential equations (ODEs) and partial differential equations (PDEs). ODEs involve a single independent variable, while PDEs involve multiple independent variables.

3. How do I solve a DE problem?

The method of solving a DE problem depends on the type of equation and its complexity. Some common techniques include separation of variables, substitution, and using an integrating factor. It is also helpful to have a strong understanding of calculus and algebra.

4. What are some real-life applications of DE problems?

DE problems are widely used in various fields to model real-life situations. For example, in physics, they are used to model the motion of objects, in economics, they can be used to predict market trends, and in biology, they can be used to model population growth.

5. What are some resources for learning about DE problems?

There are many online resources available for learning about DE problems, such as textbooks, online courses, and video tutorials. It is also helpful to practice solving different types of DE problems to improve your understanding and skills.

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