Help with Limit Test | Solving Limits

In summary, a limit test is a mathematical method used to determine the behavior of a function at a specific value or point. It is important to solve limits in order to understand the overall behavior of a function and for various applications in mathematics. The three main types of limits are one-sided limits, infinite limits, and limits at infinity. Common methods for solving limits include direct substitution, factoring, rationalization, and using trigonometric identities. However, a limit may not be solvable if the function is undefined or has a removable discontinuity, or if it approaches infinity or oscillates between values.
  • #1
Llama77
113
0
I am having trouble with this limit, i am to do a Limit test but I just don't see it.


Step 1.
Lim sqrt(x) / x
x --> Infinity




Step 2.
My professor this goes down to

Lim 1 / sqrt(x)
x --> Infinity


and the limit is then 0





What I am not sure about is from steps 1 to step 2.




I tried the latex it wouldn't work for me, sorry.
 
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  • #2
Your professor simply divided the numerator and the denominator both by [itex]\sqrt{x}[/itex].
 
  • #3


No problem, I'm happy to help with understanding the limit test. The key idea behind the limit test is to simplify the original expression and then take the limit as x approaches infinity. In this case, you started with the expression sqrt(x)/x and simplified it to 1/sqrt(x). This is a valid step because we can rewrite sqrt(x) as x^(1/2) and then use the power rule for limits to simplify the expression.

So, from step 1 to step 2, you essentially just simplified the original expression using algebra and basic limit rules. The limit of 1/sqrt(x) as x approaches infinity is 0 because the denominator (sqrt(x)) grows much faster than the numerator (1). Therefore, the overall fraction approaches 0 as x gets larger and larger.

I hope this helps clarify the steps for the limit test. Just remember to simplify the original expression and then take the limit as x approaches infinity. Let me know if you have any other questions or need further assistance. Good luck with your studies!
 

FAQ: Help with Limit Test | Solving Limits

What is a limit test?

A limit test is a mathematical method used to determine the behavior of a function as it approaches a specific value or point. It helps to determine whether the function is approaching a finite value, infinity or oscillating between values.

Why is it important to solve limits?

Solving limits helps to understand the behavior of a function at a particular point, which is crucial in understanding the overall behavior of the function. It is also used in various applications of mathematics, such as finding derivatives and integrals.

What are the different types of limits?

The three main types of limits are one-sided limits, infinite limits, and limits at infinity. One-sided limits involve approaching a value from either the left or right side, while infinite limits involve approaching a value that is either positive or negative infinity. Limits at infinity involve approaching a value as the independent variable approaches infinity.

What are the common methods for solving limits?

The most commonly used methods for solving limits include direct substitution, factoring, rationalization, and using trigonometric identities. Other methods include L'Hopital's rule, squeeze theorem, and the use of Taylor series.

When can a limit not be solved?

A limit may not be solvable if the function is undefined at the point of interest or if there is a removable discontinuity. It may also be unsolvable if the function oscillates between values or if the limit approaches positive or negative infinity.

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