Examples with solutions for Domain of a Function: Find the domain of the function

Exercise #1

Given the following function:

5x2x \frac{5-x}{2-x}

Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

To determine the domain of the function 5x2x \frac{5-x}{2-x} , we need to identify and exclude any values of x x that make the function undefined. This occurs when the denominator equals zero.

  • Step 1: Set the denominator equal to zero:
    2x=0 2-x = 0
  • Step 2: Solve for x x :
    Adding x x to both sides gives 2=x 2 = x . Hence, x=2 x = 2 .

This means that the function is undefined when x=2 x = 2 . Therefore, the domain of the function consists of all real numbers except x=2 x = 2 .

Thus, the domain is: x2 x \ne 2 .

The correct answer choice is:

Yes, x2 x\ne2

Answer

Yes, x2 x\ne2

Exercise #2

Given the following function:

49+2xx+4 \frac{49+2x}{x+4}

Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

To determine the domain of the function 49+2xx+4 \frac{49 + 2x}{x + 4} , we need to focus on avoiding division by zero, which occurs when the denominator is zero.

Let's identify the denominator of the function:

  • The denominator is x+4 x + 4 .

Next, we set the denominator equal to zero and solve for x x :

  • x+4=0 x + 4 = 0
  • Subtract 4 from both sides: x=4 x = -4

This calculation shows that the function is undefined when x=4 x = -4 . Thus, the domain of the function is all real numbers except x=4 x = -4 .

Therefore, the domain of the function is x4 x \neq -4 .

In terms of the provided choices, this corresponds to choice 4:

Yes, x4 x \ne -4

Answer

Yes, x4 x\ne-4

Exercise #3

Given the following function:

235x2 \frac{23}{5x-2}

Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

To determine the domain of the function 235x2 \frac{23}{5x-2} , follow these steps:

  • Step 1: Identify where the function is undefined by setting the denominator equal to zero.
    Equation: 5x2=0 5x - 2 = 0
  • Step 2: Solve the equation for x x .

Let's perform the calculation:
Step 1: Set 5x2=0 5x - 2 = 0 .

Step 2: Solve for x x by adding 2 to both sides:
5x=2 5x = 2

Next, divide both sides by 5:
x=25 x = \frac{2}{5}

This shows that the function is undefined at x=25 x = \frac{2}{5} , thus excluding this point from the domain of the function.

The domain of 235x2 \frac{23}{5x-2} consists of all real numbers except x=25 x = \frac{2}{5} .

Therefore, the domain is expressed as x25 x \ne \frac{2}{5} .

Considering the multiple-choice options, the correct choice is:

Yes, x25 x\ne\frac{2}{5}

Answer

Yes, x25 x\ne\frac{2}{5}

Exercise #4

Does the given function have a domain? If so, what is it?

9x4 \frac{9x}{4}

Video Solution

Step-by-Step Solution

Since the function's denominator equals 4, the domain of the function is all real numbers. This means that any one of the x values could be compatible.

Answer

No, the entire domain

Exercise #5

Look at the following function:

5x \frac{5}{x}

Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

Since the unknown variable is in the denominator, we should remember that the denominator cannot be equal to 0.

In other words, x0 x\ne0

The domain of the function is all those values that, when substituted into the function, will make the function legal and defined.

The domain in this case will be all real numbers that are not equal to 0.

Answer

Yes, x0 x\ne0

Exercise #6

Given the following function:

5+4xx2 \frac{5+4x}{x^2}

Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

To determine the domain of the function 5+4xx2 \frac{5+4x}{x^2} , we need to identify values of x x that cause the denominator to be zero, as the function is undefined for these values.

Step 1: Set the denominator equal to zero:

x2=0 x^2 = 0

Step 2: Solve for x x :

Taking the square root of both sides gives x=0 x = 0 .

The function is undefined at x=0 x = 0 , so we must exclude this value from the domain.

Thus, the domain of the function is all real numbers except x=0 x = 0 .

The domain can be expressed as: x0 x \ne 0 .

Therefore, the correct answer is option 3: Yes, x0 x \ne 0 .

Answer

Yes, x0 x\ne0

Exercise #7

Look at the following function:

5+4x2+x2 \frac{5+4x}{2+x^2}


Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

Since the denominator is positive for all x x , the domain of the function is the entire domain.

That is, all values of x x . Therefore, there is no domain limits.

Answer

No, the entire domain

Exercise #8

Given the following function:

8+8x(x+6)2 \frac{8+8x}{(x+6)^2}

Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

To determine the domain of the function 8+8x(x+6)2\frac{8+8x}{(x+6)^2}, we must find the values of xx that make the function undefined.

This function is a rational function with the numerator 8+8x8+8x and the denominator (x+6)2(x+6)^2. A rational function is undefined where its denominator is equal to zero.

Therefore, we need to solve for xx where the denominator equals zero:

  • Set the denominator equal to zero: (x+6)2=0(x+6)^2 = 0.
  • Take the square root of both sides, resulting in x+6=0x+6 = 0.
  • Solve for xx by subtracting 6 from both sides: x=6x = -6.

This calculation shows that the function is undefined when x=6x = -6. Therefore, the domain of the function includes all real numbers except x=6x = -6.

Thus, the domain of the function is all real numbers except x6x \ne -6.

The correct choice is:

Yes, x6 x\ne-6

.

Answer

Yes, x6 x\ne-6

Exercise #9

Given the following function:

65(2x2)2 \frac{65}{(2x-2)^2}

Does the function have a domain? If so, what is it?

Video Solution

Step-by-Step Solution

The denominator of the function cannot be equal to 0.

Therefore, we will set the denominator equal to 0 and solve for the domain:

(2x2)20 (2x-2)^2\ne0

2x2 2x\ne2

x1 x\ne1

In other words, the domain of the function is all numbers except 1.

Answer

Yes, x1 x\ne1

Exercise #10

Given the following function:

5+4x(x3)2 \frac{5+4x}{(x-3)^2}

Does the function have a domain? If so, what is it?

Video Solution

Answer

Yes, x3 x\ne3