Constant Functions: ε-δ Proof for Continuity

In summary, a constant function is a type of mathematical function where every output value is the same, regardless of the input value. To prove continuity for a constant function using ε-δ definition, we need to show that for any ε > 0, there exists a δ > 0 such that for all x within δ of the given input value, the output values do not deviate from the constant value by more than ε. A constant function cannot be discontinuous as it always has the same output value for any given input value. It differs from a linear function in that a linear function has a constant rate of change (slope) between the input and output values. The significance of using ε-δ definition for proving continuity is that it
  • #1
Niles
1,866
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Homework Statement


Hi all

How can I show that a constant function defined on a closed interval is continuous on that same interval using a ε-δ proof?

I have f(x)=c on the interval. Then I write

f(x)-f(a) = c-c = 0

for some point a in the interval. But what to do from here?
 
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  • #2
This is a very easy proof. Isn't 0 < epsilon for any positive epsilon?
 

FAQ: Constant Functions: ε-δ Proof for Continuity

What is the definition of a constant function?

A constant function is a type of mathematical function where every output value is the same, regardless of the input value. This means that the graph of a constant function is a horizontal line.

How do you prove continuity for a constant function using ε-δ definition?

To prove continuity for a constant function using ε-δ definition, we need to show that for any ε > 0, there exists a δ > 0 such that for all x within δ of the given input value, the output values do not deviate from the constant value by more than ε.

Can a constant function be discontinuous?

No, a constant function cannot be discontinuous as it always has the same output value for any given input value. Therefore, it satisfies the definition of continuity at every point.

How does a constant function differ from a linear function?

A constant function has a constant output value regardless of the input value, while a linear function has a constant rate of change (slope) between the input and output values. In other words, a linear function is a straight line, while a constant function is a horizontal line.

What is the significance of using ε-δ definition for proving continuity?

The ε-δ definition allows us to mathematically prove the continuity of a function at a specific point. It provides a precise and rigorous way to show that a function is continuous at a given point, rather than relying on visual inspection or intuition.

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