This is a blog for my second semester pre-calculus 30s students. Have a blast!

Thursday, February 16, 2006

Scribe # 3 "Applications of Quad. Functions"

Okay lets get down to what we learned today in class. Most of what we did today in class was based on what we did this whole week with completing the square and changing expanded form into standard form using the skill of completing the square. All we did today was applied it to real life situations.
We were given a sheet and Mr. M walked us through it.

Before I get to the questions I'd like to point out some of the instructions that were given to us to help us understand. Such as read the question carefully. We were also instructed to look for any words which could help make the question clearer such as MAXIMUM or MINIMUM. And drawing a diagram can also prove useful too.

Question #1

What is the maximum rectangular area that can be enclosed by 120 m of fencing, if one of the sides of the rectangle is an existing wall?
*NOTE: the word "maximum" was used

Work and Explanation

First we must come up with a base equation.
since we know the perimeter is 120 and that the sum of the fenced sides must equal 120 we come up with equation: 2w+l= 120

Now we make a statement for l.
we do this by moving the 2w over.
l= -2w+120

Now to find w we let y = area.
y= (-2w + 120) (w)

Convert into Standard form.
To do this we will use the skill of completing the squares to convert this into standard form.
-1800=-2(w^2-6Ow + 9oo)
=-2(w-30)^2 + 1800

Understanding the vertex.
The "k" value in the vertex is the area of the rectangle.
Therefore, max area = 18OO m squared

The homework for tonight is Exercise 6. The scribe for tommorow is vincent.


Blogger Mr. Malandrakis said...


This is a great post. You summarized the lesson in a fairly simple way that most people can look at it and pretty much understand what's going on. Great job.


8:59 PM

Blogger Richy said...

Hey Steven. It's Richy. Now I get down to business. Dun Dun Dun. It's time for rate the scribe. I give your scribe a... B. Shocked. Yes I'm a hard marker. Hahaha. Why you may ask. First things first. Spelling. Right off the bat. You spelled SCRIBE wrong. Honestly... Wow... also.. These words in your post are also misspelled: tomarrow. Only one. So that is good. Hahah. Also. Your diagram needs work. I understood the question and how you got to the answer but your diagram was really confusing. I'd say use paint. And then upload the diagram. Otherwise... Great job. Your information for the question that you put made me understand the concept a bit more and your understanding of the words MAXIMUM and MINIMUM was a useful tool in your scribe. So happy days and I'll be back tomorrow. Vincent.. Your next. Hahaha

9:03 PM

Blogger John D. - #12 said...

This comment has been removed by a blog administrator.

9:11 PM

Blogger John D. - #12 said...

Great scribing Steven! I like the way you used a different variety of colours on the important parts. You might want to use Photoshop or Paint for the diagram though.

And I know Vincent's going to surprise us tomorrow. =)

9:29 PM

Blogger Jojo said...

whos next scribe

9:44 PM

Blogger vincent said...

omg I'm next?! Oh well, I'd like to try it. By the way, the homework took most of my time tonight. HAHA!

10:09 PM


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