All Algebra II Resources
Example Questions
Example Question #51 : Introduction To Functions
You cannot take the square root of a negative number.
Example Question #52 : Introduction To Functions
The function includes all possible y-values (outputs). There is nothing you can put in for y that won't work.
Example Question #53 : Introduction To Functions
Squaring an input cannot produce a negative output.
Example Question #54 : Introduction To Functions
The function includes all possible y-values (outputs). There is nothing you can put in for y that won't work.
Example Question #55 : Introduction To Functions
A number taken to a power must be positive.
Example Question #56 : Introduction To Functions
The square root of any number cannot be negative.
Example Question #57 : Introduction To Functions
The absolute value of a number cannot be negative.
Example Question #51 : Functions And Graphs
Determine the domain of the following function:
and
and
and
and
The domain is all the possible values of . To determine the domain, we need to determine what values don't work for this equation. The only value that is not allowed for this equation is 5, since that would make the denominator have a value of , and you can not divide by . Therefore, the domain of this equation is:
and
Example Question #1 : How To Find The Domain Of A Function
Give the domain of the function:
The domain of a rational function is the set of all values of for which the denominator is not equal to 0, so we set the denominator to 0 and solve for .
This is a quadratic function, so we factor the expression as , replacing the question marks with two numbers whose product is 9 and whose sum is . These numbers are , so
becomes
,
or .
This means that , or .
Therefore, 3 is the only number excluded from the domain.
Example Question #5 : How To Find The Domain Of A Function
Give the domain of the function:
The set of all real numbers.
The domain of a rational function is the set of all values of for which the denominator is not equal to 0 (the value of the numerator is irrelevant), so we set the denominator to 0 and solve for to find the excluded values.
This is a quadratic function, so we factor the expression as , replacing the question marks with two numbers whose product is 8 and whose sum is . These numbers are , so
becomes
So either
, in which case ,
or , in which case .
Therefore, 2 and 4 are the only numbers excluded from the domain.