Exploring Limits of Functions Using Tabular, Graphical, and Algebraic Methods

Tabular Method for Finding Limits

  • Evaluates function values f(x)f(x) as input values of xx closely approach a target number from both left and right directions.
  • Example Functions for Tabular Analysis:
    • f(x)=3x2+x−4f(x) = 3x^2 + x - 4 evaluated near x=1x = 1 and x=−2x = -2
    • f(x)=x−1x+1f(x) = \frac{x-1}{x+1} evaluated near x=0x = 0 and x=1x = 1

Graphical Method for Finding Limits

  • Determines whether a limit exists and finds its value by observing the visual behavior of the function graph near a specific xx-value.
  • Evaluates whether the left-hand limit lim⁡x→a−f(x)\lim_{x \to a^-} f(x) and right-hand limit lim⁡x→a+f(x)\lim_{x \to a^+} f(x) approach the same target value.

Graph of a piecewise function for visual limit evaluation

Algebraic Method for Evaluating Limits

  • Evaluates limits analytically using substitution or algebraic properties.
  • Given Limit Problems:
    • lim⁡x→1(x2+2x−1)\lim_{x \to 1} (x^2 + 2x - 1)
    • lim⁡x→−246+x\lim_{x \to -2} \frac{4}{6+x}
    • lim⁡x→0(3x2−x+5)\lim_{x \to 0} (3x^2 - x + 5)
    • lim⁡x→1xx+1\lim_{x \to 1} \frac{x}{x+1}
    • lim⁡x→43x−4\lim_{x \to 4} \frac{3}{x-4}
    • lim⁡x→2f(x)\lim_{x \to 2} f(x) where f(x)={3x−4x≤2∣x∣x>2f(x) = \begin{cases} 3x - 4 & x \le 2 \\ |x| & x > 2 \end{cases}
    • lim⁡x→2(∣x∣−3)\lim_{x \to 2} (|x| - 3)
    • lim⁡x→3(x−3)(x+2)\lim_{x \to 3} (x - 3)(x + 2)
    • lim⁡x→−1x2+4\lim_{x \to -1} \sqrt{x^2 + 4}
    • lim⁡x→3(2x2−5)\lim_{x \to 3} (2x^2 - 5)