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4.5: Limits at Infinity and Asymptotes

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    144285
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    1. Evaluate \(\displaystyle \lim_{x \to \infty} (5x^2 - 3x + 1)\).
       
    2. Evaluate \(\displaystyle \lim_{x \to -\infty} (5x^2 - 3x + 1)\).
       
    3. Evaluate \(\displaystyle \lim_{x \to \infty} (2 + x - 3x^7)\).
       
    4. Evaluate \(\displaystyle \lim_{x \to -\infty} (2 + x - 3x^7)\).
       
    5. Evaluate \(\displaystyle \lim_{x \to \infty} \dfrac{1}{3x + 6}\).
       
    6. Evaluate \(\displaystyle \lim_{x \to -\infty} \dfrac{1}{3x + 6}\).
       
    7. Evaluate \(\displaystyle \lim_{x \to \infty} \dfrac{4x + 1}{2x - 5}\).
       
    8. Evaluate \(\displaystyle \lim_{x \to -\infty} \dfrac{4x + 1}{2x - 5}\).
       
    9. Evaluate \(\displaystyle \lim_{x \to \infty} \dfrac{x^2 - 2x + 5}{3x + 7}\).
       
    10. Evaluate \(\displaystyle \lim_{x \to -\infty} \dfrac{x^2 - 2x + 5}{3x + 7}\).
       
    11. Evaluate \(\displaystyle \lim_{x \to \infty} \dfrac{2 - 4x^3 + 7x^5}{ 1 + 3x^5}\).
       
    12. Evaluate \(\displaystyle \lim_{x \to -\infty} \dfrac{2x^2 - 7x + 1}{1 - x^3}\).
       
    13. Evaluate \(\displaystyle \lim_{x \to -\infty} \dfrac{5x^4 - 3x^2 + x}{10x^2 - 4}\).
       
    14. Evaluate \(\displaystyle \lim_{x \to \infty} \dfrac{2 - 4x^3 + 7x^5}{ 1 + 3x^5}\).
       
    15. Evaluate \(\displaystyle \lim_{x \to \infty} \sqrt{4x^2 - 7x}\).
       
    16. Evaluate \(\displaystyle \lim_{x \to -\infty} \sqrt{4x^2 - 7x}\).
       
    17. Evaluate \(\displaystyle \lim_{x \to \infty} \dfrac{2x + 3}{\sqrt{x^2 + 5x}}\).
       
    18. Evaluate \(\displaystyle \lim_{x \to -\infty} \dfrac{2x + 3}{\sqrt{x^2 + 5x}}\).
       
    19. Evaluate \(\displaystyle \lim_{x \to \infty} (\sqrt{x^2 + 2} - x)\).
       
    20. Evaluate \(\displaystyle \lim_{x \to -\infty} (\sqrt{x^2 + 2} - x)\).
       
    21. Evaluate \(\displaystyle \lim_{x \to \infty} \sin x\).
       
    22. Evaluate \(\displaystyle \lim_{x \to \infty} \dfrac{\sin x}{x}\).
       
    23. Find all horizontal and vertical asymptotes of \(f(x) = \dfrac{2x}{x - 3}\).
       
    24. Find all horizontal and vertical asymptotes of \(f(x) = \dfrac{7x - 2}{x^2 + 5x + 4}\).
       
    25. Find all horizontal and vertical asymptotes of \(f(x) = \dfrac{x + 2}{x^2 - 4}\).
       
    26. Find all horizontal and vertical asymptotes of \(f(x) = \dfrac{\sqrt{9x^2 + 1}}{3x - 5}\).
       
    27. Given function \(f(x)\) graphed below, construct sign charts for \(f\), \(f'\), and \(f''\).
      A graph of the function (x+1)/(x+2).
       
    28. Given the function \(f(x)\) graphed below, construct sign charts for \(f\), \(f'\), and \(f''\).
      The graph of the function (x-1)^3/((x-1)^4 - 1).
       
    29. Given the function \(f(x)\) graphed below, construct sign charts for \(f\), \(f'\), and \(f''\).
      A piecewise function equal to -x(x+2) for x≤0 and equal to -x(x-4) for x>0.
       
    30. Given the function \(f(x)\) graphed below, construct sign charts for \(f\), \(f'\), and \(f''\).
      The graph of (x-1)^(1/3) + 1.
       
    31. Sketch the graph of a function \(f(x)\) that agrees with the properties and sign charts below.
       
      • \(f(x)\) has a vertical asymptote at \(x = 2\)
         
      • \(\displaystyle \lim_{x \to -\infty} f(x) = \lim_{x \to \infty} f(x) = -1\)
         
      Sign charts showing f(x) is negative for x<1, positive for 1<x<2, positive for 2<x<3, and negative for x>3; f'(x) is positive for x<2 and negative for x>2; and f''(x) is positive for x<2 and positive for x>2. In all sign charts, the tick marks for 2 are dashed.

    32. Sketch the graph of a function \(f(x)\) that agrees with the properties and sign charts below.
       
      • \(f(x)\) has vertical asymptotes at \(x = -3\) and \(x = 1\)
         
      • \(\displaystyle \lim_{x \to -\infty} f(x) = \lim_{x \to \infty} f(x) = 0\)
         
      Sign charts showing f(x) is positive for x<-3, negative for -3<x<-2, negative for -1<x<1, negative for 1<x<2, and positive for x>2; f'9x) is positive for x<-3, positive for -3<x<-1, negative for -1<x<1, positive for 1<x<4, and negative for x>4; and f''(x) is positive for x<-3, negative for -3<x<1, negative for 1<x<6, and positive for x>6. In all sign charts, the tick marks for -3 and 1 and dashed.

    33. Sketch the graph of a function \(f(x)\) that agrees with the properties and sign charts below.
       
      • \(f(x)\) has no vertical asymptotes
         
      • \(\displaystyle \lim_{x \to -\infty} f(x) = -\infty\) and \(\displaystyle \lim_{x \to \infty} f(x) = \infty\)
         
      Sign charts showing f(x) is negative for x<0 and positive for x>0; f'(x) is positive for x<2, negative for 2<x<3, and positive for x>3; and f''(x) is negative for x<3 and negative for x>3. The tick mark for 3 on the sign charts for f' and f'' is represented by a dotted line.
       
    34. Sketch the graph of a function \(f(x)\) that agrees with the properties and sign charts below.
       
      • \(f(x)\) has no vertical asymptotes
         
      • \(\displaystyle \lim_{x \to -\infty} f(x) = 3\) and \(\displaystyle \lim_{x \to \infty} f(x) = -1\)
         
      Sign charts showing f(x) is positive for x<-1/2 and negative for x>-1/2; f'(x) is negative for x<-1 and negative for x>-1; f''(x) is negative for x<-1 and positive for x>-1. The tick marks for -1 in the sign charts for f' and f'' are dashed.
       
    35. Consider the function \(f(x) = \dfrac{3x-3}{2-x}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    36. Consider the function \(f(x) = \dfrac{2}{x^2 - 1}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    37. Consider the function \(f(x) = \dfrac{x}{x^2-1}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    38. Consider the function \(f(x) = \dfrac{x^2}{x^2-1}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    39. Consider the function \(f(x) = \dfrac{x^2}{x^2+1}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    40. Consider the function \(f(x) = \dfrac{1}{x^3+3x^2}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    41. Consider the function \(f(x) = x^{1/3}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    42. Consider the function \(f(x) = x^{2/3}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    43. Consider the function \(f(x) = (x-1)^2(x+3)^{2/3}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.
       
    44. Consider the function \(f(x) = \dfrac{2x+2}{\sqrt{x^2+1}}\). Find all vertical and horizontal asymptotes of the function and construct sign charts for \(f\), \(f'\), and \(f''\), then sketch the graph of \(f\). Be sure to include all \(x\)-intercepts, relative extrema, inflection points, and asymptotic behavior in your graph. Confirm your result using a graphing calculator.

    4.5: Limits at Infinity and Asymptotes is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

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