Piece Functions evaluate the functi

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trey33
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Joined: Mon Oct 03, 2011 4:48 am
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Piece Functions evaluate the functi

The work sheet is called Piece functions.
It says to evaluate the functions for the given value of X.
$f(x)\, =\, \left{\begin{array}{lr}5x\, -\, 1,&\mbox{if}\,x\, <\, -2\\x\, -\, 9,&\mbox{if}\, x\, \ge\, -2\end{array}$

$\mbox{1.}\, f(-4)$. . . . .$\mbox{2.}\, f(-2)$

$\mbox{3.}\, f(0)$. . . . . .$\mbox{4.}\, f(5)$

$h(x)\, =\, \left{\begin{array}{lr}\frac{1}{2}x\, -\, 10,&\mbox{if}\, x\, \le\, 6\\-x\, -\, 1,&\mbox{if}\, x\, >\, 6\end{array}$

$\mbox{1.}\, h(1)$. . . . .$\mbox{2.}\, h(-10)$

$\mbox{3.}\, h(6)$. . . ..$\mbox{4.}\, h(0)$
I can't figure out what it wants me to do. Isn't f(x)=5x-1 if x<-2 a problem, f(x)=5(-2)-1= fx=-11
But there is no place for an answer and #1 has an f(-4).

None of this makes sense to me! can anyone tell me how to do the page? If I do plug the numbers in then problem 2 wouldn't be able to be worked because it is f(-2) and it says on the left that if x<-2

stapel_eliz
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Joined: Mon Dec 08, 2008 4:22 pm
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$f(x)\, =\, \left{\begin{array}{lr}5x\, -\, 1,&\mbox{if}\,x\, <\, -2\\x\, -\, 9,&\mbox{if}\, x\, \ge\, -2\end{array}$

$\mbox{1.}\, f(-4)$. . . . .$\mbox{2.}\, f(-2)$

$\mbox{3.}\, f(0)$. . . . . .$\mbox{4.}\, f(5)$

$h(x)\, =\, \left{\begin{array}{lr}\frac{1}{2}x\, -\, 10,&\mbox{if}\, x\, \le\, 6\\-x\, -\, 1,&\mbox{if}\, x\, >\, 6\end{array}$

$\mbox{1.}\, h(1)$. . . . .$\mbox{2.}\, h(-10)$

$\mbox{3.}\, h(6)$. . . ..$\mbox{4.}\, h(0)$
I can't figure out what it wants me to do.
It wants you to take the given x-value, look at the rule for the function, figure out which half of the rule applies to that x-value, plug that x-value into that rule, and simplify to find the requested value.

For instance, given f(-3), you would use the first half of the rule for f(x), since -3 fits into "less than -2"; given h(37), you would use the second half of the rule for h(x), since 37 fits into "more than 6". And so forth.