Prove that the lim as x goes to a of sqrtx = sqrta

  • Thread starter apiwowar
  • Start date
In summary, the conversation is about proving the limit of \lim_{x\to a}\sqrt{x}= \sqrt{a} by using latex and the hint provided. The goal is to show that for any given \epsilon > 0, there exists a \delta > 0 that satisfies the inequality |x - a| < \delta and |\sqrt{x} - \sqrt{a}| < \epsilon.
  • #1
apiwowar
96
0
can i get some help on proving this limit?
 
Mathematics news on Phys.org
  • #2
start with
sqrt(x)-sqrt(a)=(x-a)/(sqrt(x)+sqrt(a))
 
  • #3
I think it would be very helpful if you guys used latex

The question should be

Proove that [tex]\lim {x \rightarrow a} \sqrt{x} = \sqrt{a}[/tex]

And the first reply should be

start with
[tex]\sqrt{x}-\sqrt{a}=\frac{x-a}{\sqrt{x}+\sqrt{a}}[/tex]

For basic things like this, latex only takes about a minute to learn and it VERY much easier to read :)
 
  • #4
In order to prove that "[itex]\lim_{x\to a}\sqrt{x}= \sqrt{a}[/itex], you need to prove that "Given [itex]\epsilon> 0[/itex], there exist [itex]\delta> 0[/itex] such that if [itex]|x- a|< \delta[/itex] then [itex]|\sqrt{x}-\sqrt{a}|< \epsilon[/itex]".

Start from the second inequality and show (using the above hint) that you can find such a [itex]\delta[/itex].
 

What is the definition of a limit?

A limit is the value that a function approaches as the independent variable (usually denoted as x) approaches a specific value or point. It is denoted by the notation "lim" and is used to describe the behavior of a function near a particular point.

What does "sqrt" mean in this context?

"Sqrt" is shorthand for the square root function, which is the inverse of the square function. It takes a number as an input and returns the number that, when squared, gives the original number.

What is the limit as x approaches a of sqrtx?

The limit as x approaches a of sqrtx is the value that the function sqrtx approaches as the value of x gets closer and closer to the value of a. In other words, it is the value that the function gets closer and closer to as x gets closer and closer to a.

How do you prove that the limit as x approaches a of sqrtx is sqrta?

To prove that the limit as x approaches a of sqrtx is sqrta, we use the epsilon-delta definition of a limit. This involves showing that for any small positive number epsilon, there exists a small positive number delta such that if the distance between x and a (|x-a|) is less than delta, then the distance between sqrtx and sqrta (|sqrtx-sqrta|) is less than epsilon. This can be shown using algebraic manipulation and the properties of absolute value.

Why is this limit important in mathematics and science?

This limit is important in mathematics and science because it is used to understand and describe the behavior of functions near a specific point. It is a fundamental concept in calculus and is essential for calculating derivatives and integrals, which are used in many areas of math and science, such as physics, engineering, and economics.

Similar threads

Replies
15
Views
1K
  • General Math
Replies
5
Views
879
Replies
2
Views
230
  • General Math
Replies
2
Views
813
Replies
4
Views
845
  • Math POTW for University Students
Replies
1
Views
3K
Replies
4
Views
1K
Replies
21
Views
1K
Replies
3
Views
1K
  • General Math
Replies
9
Views
2K
Back
Top