When y= a constant, how do you find the interval of definition?

In summary, the conversation discusses finding the interval of definition for a linear differential equation solved using the linear equation method. It is mentioned that the solution is y=c, and unless specified otherwise, the solution is valid for all values of t. The interval of definition for a function with a constant output is the range of values allowed for the input.
  • #1
Jeff12341234
179
0
I used the linear equation method to solve a D.E. and got y=3/4 at the end. I'm asked to find the interval of definition but I don't know how to do that when Y is just a constant :/
 
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  • #2
If your solution is y=c then dy/dt must have been 0.
Unless it was specified that dy/dt=0 on some particular interval, then your solution should be valid for all t.
 
  • #3
So the interval of definition would be (-∞,∞)?

I just don't get how a function can have a domain when it's just a constant...
 
  • #4
Jeff12341234 said:
So the interval of definition would be (-∞,∞)?

I just don't get how a function can have a domain when it's just a constant...

If your function is y(t) = 3/4, it means that for any t you give the function as an input, the function returns the value 3/4. So, the domain is whatever range of values of t you are allowed to put into your function. It doesn't matter that your function happens to return a constant in this case.
 
  • #5
thanks
 
  • #6
Jeff12341234 said:
So the interval of definition would be (-∞,∞)?

I just don't get how a function can have a domain when it's just a constant...
Every function has a domain.
Mute said:
If your function is y(t) = 3/4, it means that for any t you give the function as an input, the function returns the value 3/4. So, the domain is whatever range of values of t you are allowed to put into your function. It doesn't matter that your function happens to return a constant in this case.
I wouldn't use the word "range" when you're talking about the domain, because of confusing the issue with the function's range.
 

1. What is the definition of an interval of definition?

An interval of definition is the set of all values of the independent variable for which the given function is defined. In other words, it is the range of values that can be input into the function to produce a valid output.

2. Why is it important to know the interval of definition?

Knowing the interval of definition is important because it helps us understand the limitations and restrictions of a given function. It also allows us to identify any potential discontinuities or undefined points within the function.

3. How do you determine the interval of definition for a given function?

To determine the interval of definition, you must first identify any values that would result in an undefined output. These values may include division by zero, taking the square root of a negative number, or any other operations that are not defined for certain values. The interval of definition will then be the set of all valid input values that do not result in undefined outputs.

4. Can the interval of definition change for a given function?

Yes, the interval of definition can change for a given function. This can happen when the function is modified or when a new restriction or limitation is introduced. It is important to always check for changes in the interval of definition when working with functions.

5. How does the constant value in the equation affect the interval of definition?

When y equals a constant, the interval of definition will depend on the specific value of the constant. If the constant is a real number, then the interval of definition will be all real numbers. However, if the constant is a complex number, then the interval of definition may be restricted to certain values depending on the function.

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