Domain of a Function: Find the domain of an expression with fractions

Examples with solutions for Domain of a Function: Find the domain of an expression with fractions

Exercise #1

3x:4y+6=6 \frac{3x:4}{y+6}=6

What is the field of application of the equation?

Video Solution

Step-by-Step Solution

To determine the field of application of the equation 3x:4y+6=6\frac{3x:4}{y+6}=6, we must identify values of yy for which the equation is defined.

  • The denominator of the given expression is y+6y + 6. In order for the expression to be defined, the denominator cannot be zero.
  • This leads us to solve the equation y+6=0y + 6 = 0.
  • Solving y+6=0y + 6 = 0 gives us y=6y = -6.
  • This means y=6y = -6 would make the denominator zero, thus the expression would be undefined for this value.

Therefore, the field of application, or the domain of the equation, is all real numbers except y=6y = -6.

We must conclude that y6 y \neq -6 .

Comparing with the provided choices, the correct answer is choice 3: y6 y \neq -6 .

Answer

y6 y\operatorname{\ne}-6

Exercise #2

6x+5=1 \frac{6}{x+5}=1

What is the field of application of the equation?

Video Solution

Step-by-Step Solution

To solve this problem, we will determine the domain, or field of application, of the equation 6x+5=1 \frac{6}{x+5} = 1 .

Step-by-step solution:

  • Step 1: Identify the denominator. In the given equation, the denominator is x+5 x+5 .
  • Step 2: Determine when the denominator is zero. Solve for x x by setting x+5=0 x+5 = 0 .
  • Step 3: Solve the equation: x+5=0 x+5 = 0 gives x=5 x = -5 .
  • Step 4: Exclude this value from the domain. The domain is all real numbers except x=5 x = -5 .

Therefore, the field of application of the equation is all real numbers except where x=5 x = -5 .

Thus, the domain is x5 x \neq -5 .

Answer

x5 x\operatorname{\ne}-5

Exercise #3

x+y:32x+6=4 \frac{x+y:3}{2x+6}=4

What is the field of application of the equation?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps to find the domain:

  • Step 1: Recognize that the expression x+y:32x+6=4\frac{x+y:3}{2x+6}=4 involves a fraction. The denominator 2x+62x + 6 must not be zero, as division by zero is undefined.
  • Step 2: Set the denominator equal to zero and solve for xx to find the values that must be excluded: 2x+6=02x + 6 = 0.
  • Step 3: Solve 2x+6=02x + 6 = 0:
    • 2x+6=02x + 6 = 0
    • 2x=62x = -6
    • x=3x = -3
  • Step 4: Conclude that the domain of the function excludes x=3x = -3, meaning x3x \neq -3.

Thus, the domain of the given expression is all real numbers except x=3x = -3. This translates to:

x3 x\operatorname{\ne}-3

Answer

x3 x\operatorname{\ne}-3

Exercise #4

xyz2(3+y)+4=8 \frac{xyz}{2(3+y)+4}=8

What is the field of application of the equation?

Video Solution

Step-by-Step Solution

To find the domain of the given equation xyz2(3+y)+4=8 \frac{xyz}{2(3+y)+4}=8 , we need to ensure the denominator is not zero. This means solving 2(3+y)+4=0 2(3+y) + 4 = 0 .

Let's solve this step-by-step:

  • Step 1: Simplify the expression 2(3+y)+4=0 2(3+y) + 4 = 0 .
  • Step 2: Expand to 6+2y+4=0 6 + 2y + 4 = 0 .
  • Step 3: Combine like terms to get 2y+10=0 2y + 10 = 0 .
  • Step 4: Isolate the variable y y . Subtract 10 from both sides: 2y=10 2y = -10 .
  • Step 5: Divide by 2 to solve for y y : y=5 y = -5 .

If y=5 y = -5 , the denominator becomes zero, which makes the original expression undefined.

Therefore, the value of y y must not be 5-5 for the expression to be valid. In conclusion, the restriction on y y is that y5 y \neq -5 .

The correct answer choice is: y5 y \neq -5 .

Answer

y5 y\ne-5

Exercise #5

22(2x1)=30 22(\frac{2}{x}-1)=30

What is the domain of the equation above?

Video Solution

Answer

x≠0

Exercise #6

2x3=4x 2x-3=\frac{4}{x}

What is the domain of the exercise?

Video Solution

Answer

x≠0

Exercise #7

2x+6x=18 2x+\frac{6}{x}=18

What is the domain of the above equation?

Video Solution

Answer

x≠0

Exercise #8

What is the domain of the exercise?

5x+82x6=30 \frac{5x+8}{2x-6}=30

Video Solution

Answer

x≠3

Exercise #9

Consider the following function:

3x+42x1 \frac{3x+4}{2x-1}

What is the domain of the function?

Video Solution

Answer

x12 x\ne\frac{1}{2}

Exercise #10

Look at the following function:

10x35x3 \frac{10x-3}{5x-3}

What is the domain of the function?

Video Solution

Answer

x35 x\ne\frac{3}{5}

Exercise #11

Look at the following function:

5x+24x3 \frac{5x+2}{4x-3}

What is the domain of the function?

Video Solution

Answer

x34 x\ne\frac{3}{4}

Exercise #12

Look the following function:

15x4 \frac{1}{5x-4}

What is the domain of the function?

Video Solution

Answer

x45 x\ne\frac{4}{5}

Exercise #13

Look at the following function:

2x+23x1 \frac{2x+2}{3x-1}

What is the domain of the function?

Video Solution

Answer

x13 x\ne\frac{1}{3}

Exercise #14

Given the following function:

128x4 \frac{12}{8x-4}

What is the domain of the function?

Video Solution

Answer

x12 x\ne\frac{1}{2}

Exercise #15

Look at the following function:

2010x5 \frac{20}{10x-5}

What is the domain of the function?

Video Solution

Answer

x12 x\ne\frac{1}{2}

Exercise #16

Given the following function:

2421x7 \frac{24}{21x-7}

What is the domain of the function?

Video Solution

Answer

x13 x\ne\frac{1}{3}

Exercise #17

Look at the following function:

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

What is the domain of the function?

Video Solution

Answer

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

Exercise #18

Given the following function:

8x212 \frac{8}{x-2\frac{1}{2}}

What is the domain of the function?

Video Solution

Answer

x212 x\ne2\frac{1}{2}

Exercise #19

Look at the following function:

10x12 \frac{10x}{\frac{1}{2}}

What is the domain of the function?

Video Solution

Answer

All real numbers

Exercise #20

Look at the following function:

23x14 \frac{23}{x-\frac{1}{4}}

What is the domain of the function?

Video Solution

Answer

x14 x\ne\frac{1}{4}