length times width and getting a new equation for area?

cherryperry · February 13th, 2016, 09:48 AM

So here's my problem.

l = 52 - 2w

I need to write an equation for area based on width using the above equation. What am I missing here? Whatever the equation is, I have to enter it into my calculator to see the parabola, get the vertex, etc. I just can't figure out what the equation is I'm supposed to enter.

Any info would be appreciated. Thanks!

v8archie · February 13th, 2016, 09:50 AM

$A=lw$, and $l=52-2w$, so substitute.

cherryperry · February 13th, 2016, 10:01 AM

Thanks. Still confused though!

We're using a word problem asking about 52 panels, each 1ft long. The back of a house will close in one side of the patio. The question is:

Generalize a model (equation) for calculating the length (l) in terms of the width (w).
Hint: work from perimeter: P=2l +2w

I'm assuming I'm right with the first part (l = 52 - 2w). But nothing I graph shows a parabola.

greg1313 · February 13th, 2016, 11:16 AM

What is the exact problem statement (as worded by your instructor)? Include all given information.

February 13th, 2016, 09:48 AM	#1
cherryperry Newbie Joined: May 2010 Posts: 6 Thanks: 0	length times width and getting a new equation for area? So here's my problem. l = 52 - 2w I need to write an equation for area based on width using the above equation. What am I missing here? Whatever the equation is, I have to enter it into my calculator to see the parabola, get the vertex, etc. I just can't figure out what the equation is I'm supposed to enter. Any info would be appreciated. Thanks!
$cherryperry is offline$

February 13th, 2016, 09:50 AM	#2
v8archie Math Team Joined: Dec 2013 From: Colombia Posts: 7,674 Thanks: 2654 Math Focus: Mainly analysis and algebra	$A=lw$, and $l=52-2w$, so substitute.
$v8archie is offline$

February 13th, 2016, 10:01 AM	#3
cherryperry Newbie Joined: May 2010 Posts: 6 Thanks: 0	Thanks. Still confused though! We're using a word problem asking about 52 panels, each 1ft long. The back of a house will close in one side of the patio. The question is: Generalize a model (equation) for calculating the length (l) in terms of the width (w). Hint: work from perimeter: P=2l +2w I'm assuming I'm right with the first part (l = 52 - 2w). But nothing I graph shows a parabola.
$cherryperry is offline$

February 13th, 2016, 11:16 AM	#4
greg1313 Global Moderator Joined: Oct 2008 From: London, Ontario, Canada - The Forest City Posts: 7,958 Thanks: 1146 Math Focus: Elementary mathematics and beyond	What is the exact problem statement (as worded by your instructor)? Include all given information.
$greg1313 is offline$

Thread Tools
$Show Printable Version$ Show Printable Version $Email this Page$ Email this Page
Display Modes
$Linear Mode$ Linear Mode $Hybrid Mode$ Switch to Hybrid Mode $Threaded Mode$ Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
The Definition of Length and Width	Monox D. I-Fly	Geometry	9	September 15th, 2015 01:51 AM
Calculate the length and width of a rectangle	Apple30	Geometry	8	June 24th, 2015 09:18 PM
Expressing an L-shaped area as a function of it's width?	falmarie	Algebra	2	February 10th, 2011 07:38 AM
Word problem involving width, length, circles, rectangles	ik2244	Algebra	6	November 16th, 2010 07:08 PM
reduce area, calculate new height,width	hahaha	Algebra	7	November 12th, 2007 09:38 AM