Math Problem Statement

Find the limit. (If the limit is infinite, enter '∞' or '-∞', as appropriate. If the limit does not otherwise exist, enter DNE.)

lim x→∞ 49 −

x 7 +

x

Solution

To find the limit of the given function as xx approaches infinity, let's analyze the expression step by step:

The expression is:

limx(49x7+x)\lim_{x \to \infty} \left(49 - \frac{x}{7 + x}\right)

Step 1: Simplify the fraction x7+x\frac{x}{7 + x}

Let's rewrite the fraction x7+x\frac{x}{7 + x}:

x7+x=xx(7x+1)=17x+1\frac{x}{7 + x} = \frac{x}{x \left(\frac{7}{x} + 1\right)} = \frac{1}{\frac{7}{x} + 1}

As xx approaches infinity, 7x\frac{7}{x} approaches 0. So, the fraction simplifies to:

17x+111=1\frac{1}{\frac{7}{x} + 1} \approx \frac{1}{1} = 1

Thus, the expression inside the limit becomes:

limx(491)\lim_{x \to \infty} \left(49 - 1\right)

Step 2: Final computation

Simplifying the expression:

limx(491)=48\lim_{x \to \infty} (49 - 1) = 48

Final Answer:

limx(49x7+x)=48\lim_{x \to \infty} \left(49 - \frac{x}{7 + x}\right) = 48

Would you like more details, or do you have any further questions?

Here are some related questions:

  1. What happens to limx7x7+x\lim_{x \to \infty} \frac{7x}{7+x}?
  2. How would you compute limx0x2x+7\lim_{x \to 0} \frac{x^2}{x+7}?
  3. How do you evaluate the limit of a sum of functions as xx \to \infty?
  4. What is the difference between infinite limits and limits at infinity?
  5. How would you find the limit of a product of functions as xx approaches infinity?

Tip: When dealing with limits as xx approaches infinity, it's often helpful to divide by the highest power of xx in the denominator to simplify the expression.