Math Problem Statement

Given that lim(x → +∞) f(x) = -5, lim(x → +∞) g(x) = -1, and lim(x → +∞) h(x) = -5, find the following limits: (a) lim(x → +∞) [f(x) + 8g(x)], (b) lim(x → +∞) [f(x)g(x)], (c) lim(x → +∞) 7 / g(x), (d) lim(x → +∞) (6h(x) + 5) / x^2.

Solution

The image you provided contains the following limits to evaluate:

Given: limx+f(x)=5,limx+g(x)=1,limx+h(x)=5,\lim_{x \to +\infty} f(x) = -5, \quad \lim_{x \to +\infty} g(x) = -1, \quad \lim_{x \to +\infty} h(x) = -5, we need to find the limits for the following expressions:

(a) limx+[f(x)+8g(x)]\lim_{x \to +\infty} \left[ f(x) + 8g(x) \right]

(b) limx+[f(x)g(x)]\lim_{x \to +\infty} \left[ f(x)g(x) \right]

(c) limx+7g(x)\lim_{x \to +\infty} \frac{7}{g(x)}

(d) limx+6h(x)+5x2\lim_{x \to +\infty} \frac{6h(x) + 5}{x^2}

Solution:

(a) Using the sum rule for limits: limx+[f(x)+8g(x)]=limx+f(x)+8limx+g(x)\lim_{x \to +\infty} \left[ f(x) + 8g(x) \right] = \lim_{x \to +\infty} f(x) + 8 \cdot \lim_{x \to +\infty} g(x) Substitute the given limits: =5+8(1)=58=13= -5 + 8(-1) = -5 - 8 = -13

(b) Using the product rule for limits: limx+[f(x)g(x)]=limx+f(x)limx+g(x)\lim_{x \to +\infty} \left[ f(x)g(x) \right] = \lim_{x \to +\infty} f(x) \cdot \lim_{x \to +\infty} g(x) Substitute the given limits: =(5)(1)=5= (-5) \cdot (-1) = 5

(c) Using the limit rule for rational functions: limx+7g(x)=7limx+g(x)\lim_{x \to +\infty} \frac{7}{g(x)} = \frac{7}{\lim_{x \to +\infty} g(x)} Since limx+g(x)=1\lim_{x \to +\infty} g(x) = -1, we get: 71=7\frac{7}{-1} = -7

(d) Evaluate the limit: limx+6h(x)+5x2=limx+6(5)+5x2=limx+30+5x2=limx+25x2\lim_{x \to +\infty} \frac{6h(x) + 5}{x^2} = \lim_{x \to +\infty} \frac{6(-5) + 5}{x^2} = \lim_{x \to +\infty} \frac{-30 + 5}{x^2} = \lim_{x \to +\infty} \frac{-25}{x^2} As x2x^2 tends to infinity, 25x20\frac{-25}{x^2} \to 0. Therefore: limx+25x2=0\lim_{x \to +\infty} \frac{-25}{x^2} = 0

Final Answers:

(a) 13-13
(b) 55
(c) 7-7
(d) 00

Would you like more details or have any questions?

Here are 5 related questions:

  1. How does the sum rule for limits work?
  2. Can you apply the product rule for limits to any two functions?
  3. Why does the limit of 25x2\frac{-25}{x^2} approach zero as xx approaches infinity?
  4. What happens if g(x)g(x) tends to zero in part (c)?
  5. What other limit properties can be applied to more complex functions?

Tip: Always check for indeterminate forms (like 00\frac{0}{0} or \frac{\infty}{\infty}) when calculating limits.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Limits
Algebra

Formulas

Sum Rule for Limits: lim(x→∞) [f(x) + g(x)] = lim(x→∞) f(x) + lim(x→∞) g(x)
Product Rule for Limits: lim(x→∞) [f(x)g(x)] = lim(x→∞) f(x) * lim(x→∞) g(x)
Limit of Rational Functions: lim(x→∞) [a / g(x)] = a / lim(x→∞) g(x) for non-zero limits

Theorems

Limit Properties for Sum, Product, and Rational Functions

Suitable Grade Level

Grades 11-12