Can Two Discontinuous Functions Sum to a Continuous Function?

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In summary, discontinuous functions at a number a will result in a discontinuous sum at a. The example given involves two step functions that cancel each other out at a, but this may not be a fair representation. Mathematicians may have different perspectives on this matter.
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phrances
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can you give me an example of two discontinuous functions at a number a whose sum is not discontinuous at a? :confused: thanks!:shy:
 
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i was just about to ask a question about dis. functions, and express each function as a composition, and i don't know how to do that??

if you give me a prob, i might help to see what you mean.
 
  • #3
huh?

If the functions are discontinuous at a, then their sums are not going to be continuous at a. I suppose you could have two step functions, one going up and one going down, but I don't think that is really fair because there is still a discontinunity at a... Mathematicians?
 
  • #4
Let f(x)=0 when x is not zero, and 1 when x is zero.
Let g(x)=0 when x is not zero, and -1 when x is zero.

then f+g is continuous everywhere.
 

FAQ: Can Two Discontinuous Functions Sum to a Continuous Function?

What is a discontinuous function?

A discontinuous function is a mathematical function that has one or more points in its domain where the function is not continuous. This means that there is a break or gap in the graph of the function at these points.

What causes a function to be discontinuous?

A function can be discontinuous due to several reasons, including having a removable discontinuity (the function has a hole at a certain point), a jump discontinuity (the function has a sudden change in value at a certain point), or an infinite discontinuity (the function approaches infinity or negative infinity at a certain point).

Can a discontinuous function have a limit?

Yes, a discontinuous function can have a limit. The limit of a function at a certain point is the value that the function approaches as the input value gets closer and closer to that point. A discontinuous function can have a limit at a point where it is not continuous, as long as the limit from both sides of the point exists and is equal.

How do you determine if a function is continuous or discontinuous?

To determine if a function is continuous or discontinuous, you can graph the function and look for any breaks or gaps. Alternatively, you can evaluate the limit at each point in the domain to see if it exists and is equal to the function value at that point. If the limit does not exist or is not equal to the function value, the function is discontinuous at that point.

What are some real-life examples of discontinuous functions?

Some real-life examples of discontinuous functions include a light switch (the light is either on or off, there is no in-between state), a train schedule (the train arrives at a certain time, there is no continuous travel between stations), and a jump rope (the rope is either touching the ground or not, there is no gradual decrease in height).

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