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9th grade math What is the function rule? What is the Domain?  What is the Range?

9th grade math What is the function rule? What is the Domain?  What is the Range?-example-1
User Kev Wats
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1 Answer

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21 votes

The function rule to this table is a line. We know that a line is given by the equation:


y=mx+b

where m is the slope and b is the y-intercept.

To find the slope we use the formula:


m=(y_2-y_1)/(x_2-x_1)

using the first two points of the table we have that:


m=(16-10)/(2-1)=(6)/(1)=6

Now that we have the slope we need to find the y-intercept. To find it we plug the slope and the values of the third point in the equation and solve for b:


\begin{gathered} 22=6\cdot3+b \\ b=22-18 \\ b=4 \end{gathered}

Therefore, the fucntion rule is:


y=6x+4

The domain of the function is given by all the values of x it can take:


(-\infty,\infty)

The range of the function is given by all the values the y can take:


(-\infty,\infty)

User Ndsc
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