Algebra II : Domain and Range

Study concepts, example questions & explanations for Algebra II

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Example Questions

Example Question #22 : Properties Of Functions And Graphs

Determine the domain for the function given:

Possible Answers:

Correct answer:

Explanation:

To determine the domain of the function, we must ask ourselves where x can and cannot exist. On the numerator, nothing is preventing x from existing anywhere. But the denominator of the function cannot equal zero (which would produce an undefined value for the function), so to determine at which x values this occurs, we must set the denominator equal to zero and solve for x:

(The factors of 6 that add up to 5 are 3 and 2.)

Because these are the only values that x equal for the function to exist, we make our intervals as shown below:

We use round brackets to indicate that we never include the bounds of the intervals in the domain.

Example Question #72 : Functions And Graphs

Find the range of the function:

Possible Answers:

Correct answer:

Explanation:

To determine the range of the function, we must ask ourselves where the natural logarithm is valid (what y values can it produce). The natural logarithm is never negative, so the lowest value it reaches is zero. The function has a positive one added to it, so the lowest y-value the function reaches is 1. The function has no upper bounds, so it goes to infinity.

Example Question #23 : Properties Of Functions And Graphs

Find the domain of the function given:

Possible Answers:

Correct answer:

Explanation:

To determine the domain of the function, we must consider where x cannot exist. The only limitation on the function is the denominator, which cannot equal zero. 

To find the x-values where this occurs, we must set the denominator equal to zero and solve for x:

These are the only two limitations on the domain of the function, so the domain of the function is

Note that round brackets were used for all of the intervals, because none of the bounds of the intervals are included in the domain.

Example Question #24 : Properties Of Functions And Graphs

Find the domain of the given function:

Possible Answers:

Correct answer:

Explanation:

To determine the domain of the function, we must find the x-values that would give us an undefined result when we plug them into the function. On the numerator, we know that the natural log function can never equal zero or be negative. In the denominator, we can never have a zero. With these conditions in mind, we must now find the x values that makes these undefined situations occur.

For the numerator:

 and 

For the denominator:

Now that we know where x cannot be, we can now write the domain, making sure to use round brackets for the endpoints of the intervals:

 

 

Example Question #52 : Domain And Range

Find the domain of the function:

Possible Answers:

Correct answer:

Explanation:

To find the domain of the function, we must ask ourselves where x cannot be if we want the function to be defined. 

The only limitation on the function is that we can't have zero in the denominator (this is undefined). To find the x value(s) where this occurs, we set the denominator equal to zero and solve for x:

This is the only x value that we have an undefined result for the function, so our domain is

.

Note that we use no square brackets, because we are not including the endpoints of the intervals in the domain.

Example Question #81 : Functions And Graphs

What is the range of 

Possible Answers:

All real number

Correct answer:

Explanation:

Range asked for the values of y expressed by the function. The absolute value function is always positive with respect to y. The point 0 is included in the range requiring a square bracket. Infinity is not a numerical value so it is bound by a parentheses. 

Example Question #54 : Domain And Range

What is the domain of the following equation ?

Possible Answers:

all real numbers

Correct answer:

all real numbers

Explanation:

Domain is finding the acceptable  values that will make the function generate real values.  is a linear function therefore any  values will always generate real values. Answer is all real numbers.

Example Question #55 : Domain And Range

What is the domain of the following equation ?

Possible Answers:

all real numbers

Correct answer:

all real numbers

Explanation:

Domain is finding the acceptable  values that will make the function generate real values.  is a quadratic function therefore any  values will always generate real values. Answer is all real numbers.

Example Question #56 : Domain And Range

What is the domain of the following equation ?

Possible Answers:

all real numbers

Correct answer:

all real numbers

Explanation:

Domain is finding the acceptable  values that will make the function generate real values.  is an absolute value function therefore any  values will always generate real values. Answer is all real numbers.

Example Question #57 : Domain And Range

What is the domain of the following function ?

Possible Answers:

All real numbers except 

all real numbers

Correct answer:

All real numbers except 

Explanation:

Domain is finding the acceptable  values that will make the function generate real values. Because this function is a fractional expression, we need to check the denominator. Remember, the denominator must not be zero. This would make the function undefined. 

 We only need to look at . Since we know it can't equal zero, we set that expression to zero to determine the -value that makes this function undefined.

 Subtract  on both sides.

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