Determine the Domain: Analyzing (5x+15)/(10x+1/2) for Validity

Question

Given the following function:

5x+1510x+12 \frac{5x+15}{10x+\frac{1}{2}}

What is the domain of the function?

Video Solution

Solution Steps

00:00 Does the function have a domain? And if so, what is it?
00:04 To find the domain, remember that division by 0 is not allowed
00:09 Therefore let's see what solution makes the denominator zero
00:14 Let's isolate X
00:45 Let's multiply by the reciprocal
00:53 And this is the solution to the question

Step-by-Step Solution

To find the domain of the function 5x+1510x+12 \frac{5x+15}{10x+\frac{1}{2}} , we must ensure the denominator is not zero.

The critical expression to consider is the denominator:

10x+12 10x + \frac{1}{2}

Let's solve the equation:

  1. Set the denominator equal to zero: 10x+12=0 10x + \frac{1}{2} = 0 .
  2. To clear the fraction, multiply everything by 2: 2(10x)+2(12)=0 2(10x) + 2\left(\frac{1}{2}\right) = 0 .
  3. This simplifies to: 20x+1=0 20x + 1 = 0 .
  4. Subtract 1 from both sides: 20x=1 20x = -1 .
  5. Divide by 20: x=120 x = -\frac{1}{20} .

Thus, the function is undefined when x=120 x = -\frac{1}{20} . Consequently, the domain of the function is all real numbers except x=120 x = -\frac{1}{20} .

Therefore, the solution to the problem is x120 x \ne -\frac{1}{20} .

Answer

x120 x\ne-\frac{1}{20}