Analyzing the Domain of 2x+2/9x+6: Understanding the Function's Limits

Question

Look at the following function:

2x+29x+6 \frac{2x+2}{9x+6}

What is the domain of the function?

Video Solution

Solution Steps

00:00 Does the function have a domain of definition? If so, what is it?
00:03 To find the domain of definition, remember that we cannot divide by 0
00:06 Therefore, let's find what solution makes the denominator zero
00:10 Let's isolate X
00:26 Let's factor 6 into factors 3 and 2, and 9 into factors 3 and 3
00:31 Let's simplify what we can
00:35 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we will determine the domain of the rational function by following these steps:

  • Step 1: Identify the denominator of the function, which is 9x+6 9x + 6 .
  • Step 2: Set the denominator equal to zero to find values of x x that need to be excluded from the domain: 9x+6=0 9x + 6 = 0 .
  • Step 3: Solve the equation 9x+6=0 9x + 6 = 0 for x x .
  • Step 4: To solve, subtract 6 from both sides to get 9x=6 9x = -6 .
  • Step 5: Divide each side by 9 to solve for x x , resulting in x=23 x = -\frac{2}{3} .
  • Step 6: The domain of the function excludes the value x=23 x = -\frac{2}{3} since it makes the denominator zero.

Thus, the domain of the given function is all real numbers except x=23 x = -\frac{2}{3} , expressed as x23 x \ne -\frac{2}{3} .

Therefore, the correct choice for the domain is: x23 x\ne-\frac{2}{3} .

Answer

x23 x\ne-\frac{2}{3}