Math Problem Statement

Evaluate the limit: lim_{x -> ∞} (sqrt(16x^2 + 10x - 3 - 4x + 1))

Solution

The question is asking to evaluate the following limit as xx \to \infty:

limx16x2+10x34x+1\lim_{x \to \infty} \sqrt{16x^2 + 10x - 3 - 4x + 1}

To solve this, let's follow the steps:

Step 1: Simplify the expression inside the square root.

We combine like terms inside the square root:

16x2+10x4x3+1=16x2+6x216x^2 + 10x - 4x - 3 + 1 = 16x^2 + 6x - 2

So the limit now becomes:

limx16x2+6x2\lim_{x \to \infty} \sqrt{16x^2 + 6x - 2}

Step 2: Factor out x2x^2 from inside the square root.

Since xx \to \infty, we factor x2x^2 from the terms inside the square root:

16x2+6x2=x2(16+6x2x2)\sqrt{16x^2 + 6x - 2} = \sqrt{x^2 \left(16 + \frac{6}{x} - \frac{2}{x^2}\right)}

This simplifies to:

x216+6x2x2=x16+6x2x2\sqrt{x^2} \cdot \sqrt{16 + \frac{6}{x} - \frac{2}{x^2}} = |x| \cdot \sqrt{16 + \frac{6}{x} - \frac{2}{x^2}}

Since xx \to \infty, we take x=x|x| = x (because xx is positive as it approaches infinity).

Step 3: Evaluate the limit as xx \to \infty.

As xx \to \infty, the terms 6x\frac{6}{x} and 2x2\frac{2}{x^2} approach 0. Therefore, the expression inside the square root approaches 16:

limxx16+6x2x2=x16=x4=4x\lim_{x \to \infty} x \cdot \sqrt{16 + \frac{6}{x} - \frac{2}{x^2}} = x \cdot \sqrt{16} = x \cdot 4 = 4x

Thus, the limit is:

limx4x=4\lim_{x \to \infty} 4x = 4

Step 4: Conclusion

It seems there might be a slight misinterpretation here, as none of the given options match exactly with this result. However, checking again, you may refer to the list of options carefully or look for details around the given choices.

Do you want further clarification on any step? Let me know!


Here are 5 related questions:

  1. How would the limit change if the leading coefficient of x2x^2 inside the square root were different?
  2. What is the significance of factoring out x2x^2 in the limit calculation?
  3. How can we handle limits where the highest power of xx is not x2x^2?
  4. What happens if the sign of xx changes in the expression?
  5. How would you approach limits involving more complex roots or fractions?

Tip: Always simplify the highest-degree terms in the limit to make the calculation easier.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Limits
Square Roots
Simplification of Polynomials

Formulas

lim_{x -> ∞} sqrt(ax^2 + bx + c) = sqrt(a) as x -> ∞
Simplifying expressions inside square roots

Theorems

Limit Theorem for Polynomials
Square Root Properties

Suitable Grade Level

Grades 11-12 (Pre-Calculus or Calculus)