Examine the Domain of (2x+20)/√(2x-10)

Question

Look at the following function:

2x+202x10 \frac{2x+20}{\sqrt{2x-10}}

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
00:09 Let's isolate X
00:23 And this is the solution to the question

Step-by-Step Solution

To determine the domain of the function 2x+202x10 \frac{2x+20}{\sqrt{2x-10}} , we must ensure that the expression under the square root is non-negative, because the square root of a negative number is not defined in the real numbers.

We start by analyzing the denominator, specifically the square root, 2x10\sqrt{2x-10}. For the square root to be valid (for real numbers), we require:

  • 2x100 2x-10 \geq 0

Now, solve the inequality 2x1002x - 10 \geq 0:

  • Add 10 to both sides: 2x102x \geq 10
  • Divide both sides by 2: x5x \geq 5

However, since the expression 2x102x-10 also prohibits zero in the denominator (as the square root in the denominator cannot be zero), we strictly have:

  • x>5x > 5

Thus, the domain of the function is all xx such that x>5x > 5.

Therefore, the domain of the function 2x+202x10\frac{2x+20}{\sqrt{2x-10}} is x>5 x > 5 .

Answer

x > 5