Confusion about continuity question.

Once the discontinuity at x=0 is removed, the function becomes continuous everywhere. In summary, the function g(x) = x2/x has a removable discontinuity at x=0, but the piecewise function f(x) that defines it is continuous everywhere.
  • #1
mathstudent79
9
0
1.The Question

The function f(x)=


x2/x if (x≠0)



0 if(x=0)

The Attempt at a Solution

I thought this had a removable discontinuity at x=0, because the function s2/x is not defined at x=0, and the expression can be reduced to x.

The book (one of those AP prep guides with solutions) says that it is continuous everywhere, to note that x2/x if x≠0 and lim(x->0) f = 0.

Why was I wrong?

Thanks in advance.
 
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  • #2
mathstudent79 said:
1.The Question

The function f(x)=

x2/x if (x≠0)

0 if(x=0)

The Attempt at a Solution



I thought this had a removable discontinuity at x=0, because the function s2/x is not defined at x=0, and the expression can be reduced to x.

The book (one of those AP prep guides with solutions) says that it is continuous everywhere, to note that x2/x if x≠0 and lim(x->0) f = 0.

Why was I wrong?

Thanks in advance.
The function g(x) = x2/x does have a removable discontinuity at x=0.

The piecewise function, f(x) that you give has that discontinuity removed. f(x) is defined for all x, and is continuous for all x, even for x = 0.
 
  • #3
SammyS

Thanks so much for your quick response.


So, just to be sure, once the discontinuity is removed, the function is continuous everywhere, is that right?

Thanks again.
 
  • #4
mathstudent79 said:
SammyS

Thanks so much for your quick response.


So, just to be sure, once the discontinuity is removed, the function is continuous everywhere, is that right?

Thanks again.

Yes, that's right.
 

What is continuity?

Continuity is a mathematical concept that describes the smoothness and connectedness of a function or curve. It means that there are no sudden breaks or interruptions in the graph of the function.

Why is continuity important?

Continuity is important in many areas of mathematics and science because it allows us to make predictions and analyze functions with confidence. It also helps us to understand the behavior of real-world phenomena.

What is the difference between continuity and differentiability?

Continuity and differentiability are related but distinct concepts. Continuity refers to the smoothness of a function, while differentiability refers to the existence of a derivative at a point. A function can be continuous but not differentiable, and vice versa.

What are the three conditions for continuity?

The three conditions for continuity are: 1) the function is defined at the point in question, 2) the limit of the function at that point exists, and 3) the limit equals the value of the function at that point.

How do you test for continuity?

To test for continuity, you can use the three conditions mentioned above. You can also use graphical methods such as plotting the function or using the Intermediate Value Theorem. In some cases, you may need to use algebraic methods or piecewise functions to determine continuity.

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