Math Problem Statement

find the range of 1/(sqrt(x+1))

Solution

To find the range of the function f(x)=1x+1f(x) = \frac{1}{\sqrt{x + 1}}, we need to explore the possible values that f(x)f(x) can take for all values of xx within the domain.

Step 1: Identify the Domain

The expression x+1\sqrt{x + 1} requires that x+10x + 1 \geq 0 (since the square root of a negative number is not real). Thus, we must have:

x+10x1x + 1 \geq 0 \quad \Rightarrow \quad x \geq -1

So, the domain of the function is x1x \geq -1.

Step 2: Behavior of the Function

The function can be rewritten as:

f(x)=1x+1f(x) = \frac{1}{\sqrt{x + 1}}

As xx approaches 1-1 from the right (i.e., x1+x \to -1^+), the denominator x+1\sqrt{x + 1} approaches 0. Therefore, f(x)f(x) \to \infty as x1+x \to -1^+.

As xx \to \infty, x+1\sqrt{x + 1} grows larger, causing f(x)f(x) to approach 0. Therefore, f(x)0+f(x) \to 0^+ as xx \to \infty.

Step 3: Range of the Function

Given that f(x)f(x) \to \infty as x1+x \to -1^+ and f(x)0+f(x) \to 0^+ as xx \to \infty, the function takes all positive real values between 0 and \infty. Thus, the range of the function is:

(0,)(0, \infty)

Final Answer:

The range of f(x)=1x+1f(x) = \frac{1}{\sqrt{x + 1}} is (0,)(0, \infty).

Would you like a more detailed explanation, or do you have any questions about this problem? Here are some related questions to explore:

  1. How would the range change if the function were f(x)=1x1f(x) = \frac{1}{\sqrt{x - 1}}?
  2. What happens if we modify the function to f(x)=1x+1+2f(x) = \frac{1}{\sqrt{x + 1}} + 2?
  3. How do transformations like translations and scalings affect the range of a function?
  4. Can you explain how the domain of a function affects its range?
  5. What would the range be if we had the function f(x)=1x+1f(x) = \frac{1}{\sqrt{x + 1}} for x(1,3)x \in (-1, 3)?

Tip: When analyzing the range of a function, start by identifying its domain and understanding the behavior of the function as it approaches boundary points (like limits).

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Functions
Square Roots
Range of Functions
Limits

Formulas

f(x) = 1 / sqrt(x + 1)

Theorems

Range of a function
Limits at boundary points

Suitable Grade Level

Grades 10-12