Limit Problem: Solving Lim as x goes to infinity of sqrt(x^2 + 1) / x

  • Thread starter Thread starter icosane
  • Start date Start date
  • Tags Tags
    Limit
AI Thread Summary
To solve the limit as x approaches infinity of sqrt(x^2 + 1) / x, divide both the numerator and denominator by x. This simplifies the expression to sqrt(1 + 1/x^2). As x increases, 1/x^2 approaches zero, leading to the limit equaling 1. Multiple responses emphasize this approach, confirming its validity. The final limit is therefore 1.
icosane
Messages
48
Reaction score
0

Homework Statement



Lim as x goes to infinity of sqrt(x^2 + 1) / x


The Attempt at a Solution



know you are supposed to divide by the highest power of x, but how does that work when you have an x^2 within a sqrt?
 
Physics news on Phys.org
Try writing x2+1 as x2(1+1/x2).

See if that helps.
 
And remember that (1/x)\sqrt{x^2+ 1}= \sqrt{(1/x^2)(x^2+ 1}
 
put your x into the square root by making it X^2...then it will be easy because you will get something like
limit x--->infinity sqrt(1+1/X^2)
and when x goes to infinity 1/X^2 goes to zero
so your final limit will go to 1
hope you got it!
 
You've got three responses saying the same thing in different ways!
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
Back
Top