Uncover the Domain of a Radical Rational Function: (x+7)/√(x-7)

Question

Look at the following function:

x+7x7 \frac{x+7}{\sqrt{x-7}}

What is the domain of the function?

Video Solution

Solution Steps

00:00 Does the function have a domain? If so, what is it?
00:04 Root must be for a positive number greater than 0
00:08 Let's isolate X
00:15 And this is the solution to the question

Step-by-Step Solution

To determine the domain of the function x+7x7\frac{x+7}{\sqrt{x-7}}, we need to ensure the denominator remains defined and non-zero. As follows:

First, focus on the denominator x7\sqrt{x-7}. The expression under the square root, x7x-7, must be greater than zero for the square root to be defined and not produce zero in the denominator:

  • x7>0x - 7 > 0

This simplifies to:

  • x>7x > 7

Since the expression under the square root must always be positive for this rational function to be defined, and x7\sqrt{x-7} in the denominator implies it cannot equal zero, our analysis is complete. Consequently, the domain of the function is the set of all xx such that:

The domain of the function is x>7x > 7.

Answer

x > 7