Finding the Domain of the Function: Simplifying 9/(3x+1/2)

Question

Look at the following function:

93x+12 \frac{9}{3x+\frac{1}{2}}

What is its domain?

Video Solution

Solution Steps

00:00 Does the function have a domain? And if so, what is it?
00:03 To find the domain, remember that division by 0 is not allowed
00:07 Therefore let's see what solution zeros the denominator
00:10 Let's isolate X
00:30 Multiply by the reciprocal, making sure to multiply numerator by numerator and denominator by denominator
00:39 And this is the solution to the question

Step-by-Step Solution

To find the domain of the function 93x+12 \frac{9}{3x+\frac{1}{2}} , we need to determine for which values of x x the expression is defined.

1. The function is of the form 93x+12 \frac{9}{3x+\frac{1}{2}} . A fraction is undefined if its denominator is zero.

2. Set the denominator of the function equal to zero: 3x+12=0 3x + \frac{1}{2} = 0 .

3. Solve the equation for x x :

  • First, subtract 12 \frac{1}{2} from both sides: 3x=12 3x = -\frac{1}{2} .
  • Next, divide both sides by 3 to solve for x x : x=12×13=16 x = -\frac{1}{2} \times \frac{1}{3} = -\frac{1}{6} .

4. The solution x=16 x = -\frac{1}{6} indicates that at this value, the denominator becomes zero, making the function undefined. Therefore, x16 x \ne -\frac{1}{6} .

Thus, the domain of the function is all real numbers except x=16 x = -\frac{1}{6} .

The correct answer is x16 x \ne -\frac{1}{6} , which matches choice 2: x16 x\ne-\frac{1}{6} .

Answer

x16 x\ne-\frac{1}{6}