Is the Limit of the Sum Always the Sum of the Limits?

In summary, the student's statement that "the limit of the sum of two functions is the sum of the limits of the functions" is not always correct, as there are exceptions. For expressing the limit of (x-1)^3 as x approaches 3, two different ways are to say it is 8 or to approach it from the left and right.
  • #1
Jacobpm64
239
0
I have a few conceptual questions on limits that i need help with..

1. A student in your class says, "The limit of the sum of two functions is the sum of the limits of the functions." When is the statement not correct?

I'm not sure. I thought it was always correct because doesn't one of the theorems actually say that the limit of the sum of two functions is the sum of the limits of the functions. Is there an exception I'm missing?

2. Express the limit of (x-1)^3 as x approaches 3 in two different ways.

hmm.. I'm not sure what they want right here
 
Physics news on Phys.org
  • #2
1. yes you are missing something. try rereading your notes.

2. no, i don't know either. the limit is 8. perhaps they also want you to say it is 16/2, who knows.
 
  • #3
i think for number 1.. lim f + g = lim f + lim g ... if lim f and lim g both exist.

I still don't know about #2 though
 
  • #4
For 2 they probably want the limit from the left, and from the right.
 
  • #5
Well, one way to express "the limit of (x-1)^3 as x approaches 3" is "8"!
 

FAQ: Is the Limit of the Sum Always the Sum of the Limits?

What is a limit?

A limit is a fundamental concept in calculus that describes the behavior of a function as its input approaches a certain value. It represents the value that a function is approaching, rather than the value it is actually at.

How is a limit calculated?

A limit is calculated by evaluating the function at values closer and closer to the desired input value. As these values get closer, the limit can be approximated by the function's output at those values.

What is the difference between a limit and a derivative?

A limit is a concept that describes the behavior of a function at a single point, while a derivative describes the behavior of a function over an interval. In other words, a derivative is the rate of change of a function, while a limit is the value that a function is approaching.

What is the significance of limits in calculus?

Limits are important in calculus because they allow us to understand and analyze the behavior of functions, particularly at points where the function may not be defined. They also play a crucial role in the definition and calculation of derivatives and integrals.

Can limits help us solve real-world problems?

Yes, limits have many practical applications in fields such as physics, engineering, and economics. They can be used to model and analyze real-world situations, such as the growth of a population or the trajectory of a moving object.

Similar threads

Back
Top