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Example Questions
Example Question #1 : Determine If A Relation Is A Function
Consider a family consisting of a two parents, Juan and Oksana, and their daughters Adriana and Laksmi. A relation is true whenever is the child of . Which of the following is not true?
If the two parents had only one daughter, the relation would be a function.
Even if the two parents had only one daughter, the relation would not be a function.
(Laksmi,Adriana) does not hold because Adriana is not Laksmi's child.
The relation is not a function because (Laksmi,Juan) and (Laksmi,Oksana) both hold.
(Adriana,Laksmi) does not hold because Laksmi is not Adriana's child and is a boy.
Even if the two parents had only one daughter, the relation would not be a function.
The statement
"Even if the two parents had only one daughter, the relation would not be a function."
is not true because if they had only one daughter, say Adriana, then the only relations that would exist would be (Juan, Adriana) and (Oksana,Adriana), which defines a function.
Example Question #3 : Determine If A Relation Is A Function
Which of the following relations is not a function?
The definition of a function requires that for each input (i.e. each value of ), there is only one output (i.e. one value of ). For , each value of corresponds to two values of (for example, when , both and are correct solutions). Therefore, this relation cannot be a function.
Example Question #2 : Determine If A Relation Is A Function
Given the set of ordered pairs, determine if the relation is a function
No
Cannot be determined
Yes
No
A relation is a function if no single x-value corresponds to more than one y-value.
Because the mapping from goes to and
the relation is NOT a function.
Example Question #1 : Determine If A Relation Is A Function
What equation is perpendicular to and passes throgh ?
First find the reciprocal of the slope of the given function.
The perpendicular function is:
Now we must find the constant, , by using the given point that the perpendicular crosses.
solve for :
Example Question #5 : Determine If A Relation Is A Function
Is the following relation of ordered pairs a function?
Yes
No
Cannot be determined
Yes
A set of ordered pairs is a function if it passes the vertical line test.
Because there are no more than one corresponding value for any given value, the relation of ordered pairs IS a function.
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