Math Problem Statement

lim_{x \to 1^+} \left( \frac{9}{x^2 - x} - \frac{x}{x - 1} \right)

Solution

The limit expression given in the image is:

limx1+(9x2xxx1)\lim_{x \to 1^+} \left( \frac{9}{x^2 - x} - \frac{x}{x - 1} \right)

Let's break this down and solve step by step.

Step 1: Simplify each term

  • The first term is 9x2x\frac{9}{x^2 - x}, which can be factored: x2x=x(x1)x^2 - x = x(x - 1) So the first term becomes: 9x(x1)\frac{9}{x(x - 1)}

  • The second term is xx1\frac{x}{x - 1}.

Step 2: Combine the terms

Both terms have the denominator x1x - 1, so let's combine them: 9x(x1)xx1=9x2x(x1)\frac{9}{x(x - 1)} - \frac{x}{x - 1} = \frac{9 - x^2}{x(x - 1)} The numerator 9x29 - x^2 can be rewritten as: 9x2=(3x)(3+x)9 - x^2 = (3 - x)(3 + x) Thus, the expression becomes: (3x)(3+x)x(x1)\frac{(3 - x)(3 + x)}{x(x - 1)}

Step 3: Evaluate the limit as x1+x \to 1^+

As xx approaches 1 from the right, we need to check if there are any issues with division by zero. Notice that the denominator contains x(x1)x(x - 1), and as x1+x \to 1^+, x1x - 1 approaches 0. This suggests that the limit might involve an infinite behavior.

Let’s analyze each part:

  • As x1+x \to 1^+, the factor x1x - 1 in the denominator becomes very small and positive, so the whole expression tends towards infinity.

Thus, the limit tends to -\infty as x1+x \to 1^+, because the numerator (3x)(3+x)(3 - x)(3 + x) evaluates to 4 when x=1x = 1, but the denominator tends to 0 from the positive side.

Final Answer:

limx1+(9x2xxx1)=\lim_{x \to 1^+} \left( \frac{9}{x^2 - x} - \frac{x}{x - 1} \right) = -\infty

Would you like further details or have any other questions?

Here are five related questions to explore this topic further:

  1. What happens if you evaluate the limit as x1x \to 1^-?
  2. How can L'Hôpital's Rule be applied to similar limit problems?
  3. What does it mean for a limit to approach infinity or negative infinity?
  4. How would the limit change if the numerator in one of the fractions was modified?
  5. How can factoring be useful in solving complex limit problems?

Tip: Always check for indeterminate forms when calculating limits involving fractions, especially if the denominator tends to zero.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Limits
Algebra
Factoring
Infinity

Formulas

lim_{x \to a} \frac{f(x)}{g(x)}
(a^2 - b^2) = (a - b)(a + b)

Theorems

Limit Theorem
Factoring Theorem

Suitable Grade Level

Grade 12 - College Level