Math Problem Statement

lim_{x \to 2} (x^2 - 4)/(x-2)

Solution

To evaluate the limit:

limx2x24x2,\lim_{x \to 2} \frac{x^2 - 4}{x - 2},

we notice that direct substitution of x=2x = 2 leads to an indeterminate form 00\frac{0}{0}. To resolve this, we factorize the numerator x24x^2 - 4 as a difference of squares:

x24=(x2)(x+2).x^2 - 4 = (x - 2)(x + 2).

Substituting this factorization into the limit expression:

x24x2=(x2)(x+2)x2.\frac{x^2 - 4}{x - 2} = \frac{(x - 2)(x + 2)}{x - 2}.

For x2x \neq 2, the (x2)(x - 2) terms cancel out, leaving:

\frac{x^2 - 4}{x - 2} = x + 2 \quad \text{(for x \neq 2)}.

Now, we evaluate the limit:

limx2(x+2)=2+2=4.\lim_{x \to 2} (x + 2) = 2 + 2 = 4.

Final Answer:

limx2x24x2=4.\lim_{x \to 2} \frac{x^2 - 4}{x - 2} = 4.


Would you like further explanation or additional examples?

Here are 5 related questions for practice:

  1. Evaluate limx3x29x3\lim_{x \to 3} \frac{x^2 - 9}{x - 3}.
  2. Find the limit: limx1x31x1\lim_{x \to 1} \frac{x^3 - 1}{x - 1}.
  3. Compute limxax2a2xa\lim_{x \to a} \frac{x^2 - a^2}{x - a}.
  4. Determine the limit limx0x22xx\lim_{x \to 0} \frac{x^2 - 2x}{x}.
  5. Solve limx1x3+1x+1\lim_{x \to -1} \frac{x^3 + 1}{x + 1}.

Tip:

When encountering indeterminate forms, look for algebraic simplifications such as factoring, expanding, or using conjugates to simplify the expression.

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Math Problem Analysis

Mathematical Concepts

Limits
Factoring Polynomials
Difference of Squares
Indeterminate Forms

Formulas

Difference of squares: a^2 - b^2 = (a - b)(a + b)

Theorems

Limit Laws
Factoring and Simplification Techniques

Suitable Grade Level

Grades 10-12