Last question!

Question

Last question!

thatonegirl_ · Answer

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thatonegirl_ · Answer

My first question is does the middle line count?

mathstudent55 · Answer

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mathstudent55 · Answer

Yes, it does.
The middle piece is part of the total of 200 ft.

thatonegirl_ · Answer

Okay thx. So you divided the top by 2 to account for the bottom piece too?

mathstudent55 · Answer

Correct.
Three pieces of x length will be used for the three vertical pieces.
Then 200 - 3x is left.
That has to be divided by 2, for the top and bottom.

thatonegirl_ · Answer

Okay gotcha. Then what?

mathstudent55 · Answer

Now you need to write an equation for the area of the entire corral area.

thatonegirl_ · Answer

$$A=x(\frac{ 200-3x }{ 2} )$$

mathstudent55 · Answer

Correct.
Multiply it out and write it the form 

y = ax^2 + bx + c

thatonegirl_ · Answer

$$A=-\frac{ 3x^2 }{ 2 } +100x$$

mathstudent55 · Answer

Good.
You see that the leading coefficient is negative, so this is a parabola that opens downward.

thatonegirl_ · Answer

Oh yeah

thatonegirl_ · Answer

So i would graph this, then find the topmost point?

mathstudent55 · Answer

Yes, but we can just figure it out with algebra.
Notice that there is no constant term.
There are only term terms, an x^2 term and an x term.
What is A when x = 0?

thatonegirl_ · Answer

0?

mathstudent55 · Answer

Yes.
We have this:
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