Solve the given differential equations or initial-value problems

In summary, the conversation discusses two questions related to solving differential equations or initial-value problems, specifically focusing on separable first-order differential equations. The first equation given may have a typo, and the second equation is shown to be separable. The conversation ends with a reminder that understanding the material is key to solving the problems.
  • #1
Marwanx
4
0
Hello guys,

I have these two questions that I spent s much time to solve them but couldn't.


solve the given differential equations or initial-value problems

* dy/dx = x/t


* dy/dt = 3 + 5y

It's about SEPARABLE FIRST-ORDER DIFFERENTIAL equations.

Thank you so much,
 
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  • #2
first try to solve second eq. dy/dt -5y=3 is a linear differansial eq. , you will get t(y)
and put t(y) in the first eq. like: t(y).dy=x.dx, integrate this, here is the solution.
 
  • #3
It looks like you have two completely separate question there?

Is there a typo or something in the first equation?

The second equation: it's separable! dy/(3 + 5y) = dt. If you can't solve that question, you haven't understood the material.
 
  • #4
Marwanx said:
Hello guys,

I have these two questions that I spent s much time to solve them but couldn't.


solve the given differential equations or initial-value problems

* dy/dx = x/t


* dy/dt = 3 + 5y

It's about SEPARABLE FIRST-ORDER DIFFERENTIAL equations.

Thank you so much,
Your first equation doesn't make sense. There shouldn't be an "x" in the equation if nothing else is said about "x". You probably mean dy/dx= y/t.

These are called "separable" because you can separate y and t. In the first equation dy/dx= y/t becomes (1/y)dy/dt= t and now you can treat the derivative dy/dt as the ratio of differentials (dy)/(dt) so that (1/y)dy= t dt and integrate both sides, (1/y)dy with respect to y and t dt with respect to t.

Similarly, dy/dt= 3+ 5y becomes dy/(3+ 5y)= dt in "differential form" and you can again integrate both sides.
 
  • #5


I understand that solving differential equations can be challenging and time-consuming. In order to solve these two equations, we need to use the method of separation of variables. This method involves isolating the dependent and independent variables on opposite sides of the equation and then integrating both sides. For the first equation, we can rewrite it as dy/dx = 1/t * x. We can then separate the variables and integrate both sides to get y = ln(t) + C, where C is the constant of integration. For the second equation, we can rewrite it as dy/dt - 5y = 3. Again, we can separate the variables and integrate both sides to get y = (3/5) + Ce^(5t), where C is the constant of integration. I hope this helps in solving these equations. Good luck!
 

1. What is a differential equation?

A differential equation is a mathematical equation that describes the relationship between a function and its derivatives. It is used to model many natural phenomena and physical systems.

2. What is the process for solving a differential equation?

The process for solving a differential equation involves finding an expression for the unknown function that satisfies the equation. This usually involves applying various mathematical techniques, such as separation of variables, substitution, or integrating factors.

3. What is an initial-value problem?

An initial-value problem is a type of differential equation that includes an initial condition, specifying the value of the unknown function at a particular point. The solution to an initial-value problem is a function that satisfies both the differential equation and the initial condition.

4. What is the significance of solving differential equations?

Solving differential equations allows us to understand and predict the behavior of various systems and processes, including physical, biological, and economic systems. It also plays a crucial role in many areas of science, engineering, and technology.

5. What are the different methods for solving differential equations?

Some common methods for solving differential equations include separation of variables, substitution, integrating factors, and series solutions. Other techniques, such as Laplace transforms and numerical methods, are also used for more complex or difficult problems.

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