Limit of function with rational

In summary, the conversation discusses a problem with rationalizing a function involving a square root. The person suggests multiplying the numerator and denominator by the conjugate, but is unsure how to proceed. Another person suggests rationalizing the numerator and denominator separately. The problem is eventually solved by factoring.
  • #1
iloveannaw
45
0

Homework Statement


the title says it all

[tex]x \rightarrow 4[/tex]

for [tex]f\left(x\right) = \frac{\sqrt{1+2x}-3}{\sqrt{x}-2}[/tex]

I have multiplied both top and bottom by conjugate, [tex]\sqrt{x}+2[/tex]:

[tex]f\left(x\right) = \frac{\sqrt{x(1+2x)}+2\sqrt{1+2x} -3\sqrt(x)-6}{x-4}[/tex]but don't know how to take this further. Dividing both numerator and denominator by x doesn't help.
 
Physics news on Phys.org
  • #2
iloveannaw said:

Homework Statement


the title says it all

[tex]x \rightarrow 4[/tex]

for [tex]f\left(x\right) = \frac{\sqrt{1+2x}-3}{\sqrt{x}-2}[/tex]

I have multiplied both top and bottom by conjugate, [tex]\sqrt{x}+2[/tex]:

[tex]f\left(x\right) = \frac{\sqrt{x(1+2x)}+2\sqrt{1+2x} -3\sqrt(x)-6}{x-4}[/tex]


but don't know how to take this further. Dividing both numerator and denominator by x doesn't help.

Try rationalizing the numerator first, then the denominator. That's what I would do.
 
  • #3
thankyou!
 
  • #4
No problem. Incidentally, since I didn't carry it all the way out myself, did it work?
 
  • #5
yes, that's why I'm so pleased - it just needed a bit of factoring after doing it your way. cheers
 
  • #6
Awesome!

Have a great day.
 

Related to Limit of function with rational

1. What is the definition of a limit of a function with rational?

A limit of a function with rational is the value that a function approaches as the input approaches a certain value, also known as the limit point. This value can be determined by evaluating the function at values that are closer and closer to the limit point.

2. How is the limit of a function with rational calculated?

The limit of a function with rational can be calculated by using the algebraic definition of a limit, which involves evaluating the function at values that are closer and closer to the limit point, and then simplifying the resulting expression.

3. What is the relationship between limits of functions with rational and continuity?

Limits of functions with rational are closely related to continuity. A function is said to be continuous at a point if the limit of the function at that point exists and is equal to the value of the function at that point. If a function is not continuous at a point, it means that the limit of the function at that point does not exist or is not equal to the value of the function at that point.

4. Can a limit of a function with rational be undefined?

Yes, a limit of a function with rational can be undefined. This can happen if the function has a vertical asymptote at the limit point, meaning that the function approaches positive or negative infinity as the input approaches the limit point.

5. How can the limit of a function with rational be used in real-world applications?

Limits of functions with rational have many applications in the real world. For example, they can be used in engineering to determine the maximum load a structure can withstand, in physics to calculate instantaneous velocity and acceleration, and in economics to analyze supply and demand functions. They are also used in many other fields to model and analyze real-world phenomena.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
17
Views
797
  • Precalculus Mathematics Homework Help
Replies
6
Views
145
  • Precalculus Mathematics Homework Help
Replies
13
Views
421
  • Precalculus Mathematics Homework Help
Replies
3
Views
717
  • Precalculus Mathematics Homework Help
Replies
10
Views
715
  • Precalculus Mathematics Homework Help
Replies
1
Views
91
  • Precalculus Mathematics Homework Help
Replies
8
Views
807
  • Precalculus Mathematics Homework Help
Replies
3
Views
851
  • Precalculus Mathematics Homework Help
Replies
9
Views
1K
  • Precalculus Mathematics Homework Help
Replies
10
Views
418
Back
Top