Author Topic: Math Heeelppp!!  (Read 3016 times)

Offline al noor

  • SF Citizen
  • ***
  • Posts: 158
  • Reputation: 33
Math Heeelppp!!
« on: November 08, 2009, 03:07:12 pm »
Can any1 solve these problems for me as i want to check if my answrs are right ;)
Thanyou in advance :D
« Last Edit: November 08, 2009, 03:25:02 pm by al noor »

Offline Tyserius

  • Actuary Wannabe
  • SF Geek
  • ****
  • Posts: 318
  • Reputation: 383
  • Gender: Male
  • You are who you choose to become
Re: Math Heeelppp!!
« Reply #1 on: November 08, 2009, 04:46:26 pm »
Okay, will try to help solve it for you. :) Give me a while.
Take it easy and go slow and steady.

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Math Heeelppp!!
« Reply #2 on: November 08, 2009, 04:54:34 pm »
bridge question a)50
b)250(500-250)800+60

These numbers seem incredible. For the next part I get a ridiculous percentage error.
Are you sure these questions are correct?

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Math Heeelppp!!
« Reply #3 on: November 08, 2009, 04:56:22 pm »
It says y = x(500-x)800 + 50
should it say y = x(500-x)/800 + 50

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Math Heeelppp!!
« Reply #4 on: November 08, 2009, 05:09:31 pm »
b)i)30
ii)400
iii)10 and 50
iv) presumably x-60 so loss =-60^2+50+50-500=-500
vi)-x(x-30)^2+400
max profit of 400 at x=30

Offline al noor

  • SF Citizen
  • ***
  • Posts: 158
  • Reputation: 33
Re: Math Heeelppp!!
« Reply #5 on: November 08, 2009, 05:13:09 pm »
bridge question a)50
b)250(500-250)800+60

These numbers seem incredible. For the next part I get a ridiculous percentage error.
Are you sure these questions are correct?

Well thats the worksheet that the teacher gave us

Offline al noor

  • SF Citizen
  • ***
  • Posts: 158
  • Reputation: 33
Re: Math Heeelppp!!
« Reply #6 on: November 08, 2009, 05:15:07 pm »
b)i)30
ii)400
iii)10 and 50
iv) presumably x-60 so loss =-60^2+50+50-500=-500
vi)-x(x-30)^2+400
max profit of 400 at x=30

Thnkz aloott astar

Offline Tyserius

  • Actuary Wannabe
  • SF Geek
  • ****
  • Posts: 318
  • Reputation: 383
  • Gender: Male
  • You are who you choose to become
Re: Math Heeelppp!!
« Reply #7 on: November 08, 2009, 05:16:11 pm »
Here you go! For the first page :)

Dear astarmathsandphysics,

Would you mind helping me check it as well, sir? xD Just in case I make mistakes. By the way, the equation is fractional :)
Take it easy and go slow and steady.

Offline Tyserius

  • Actuary Wannabe
  • SF Geek
  • ****
  • Posts: 318
  • Reputation: 383
  • Gender: Male
  • You are who you choose to become
Re: Math Heeelppp!!
« Reply #8 on: November 08, 2009, 05:18:24 pm »
Dear al noor,

For the 2nd question part (a), once again, your graph is a parabolic curve with the symmetry at x=30. Therefore, that's where your maximum point will lie which is (30,400). It should begin at -500 and end there as well therefore, the starting point of the graph would be (0,-500) and the end point would be (60,-500)

EDIT : For the 2nd question part (c), the expression should be (x-30)^2 -400. There shouldn't be a -x outside. The connection is as stated by astar. :) I'm trying to figure out the part where they ask for the loss when toys are given away though.
« Last Edit: November 08, 2009, 05:24:18 pm by Tyserius »
Take it easy and go slow and steady.

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Math Heeelppp!!
« Reply #9 on: November 08, 2009, 05:23:05 pm »
It should say y = x(500-x)/800 + 50

Offline Tyserius

  • Actuary Wannabe
  • SF Geek
  • ****
  • Posts: 318
  • Reputation: 383
  • Gender: Male
  • You are who you choose to become
Re: Math Heeelppp!!
« Reply #10 on: November 08, 2009, 05:25:08 pm »
It should say y = x(500-x)/800 + 50

Yep! I opened it with Microsoft 2007 and it shows a fractional equation :)
Take it easy and go slow and steady.

Offline astarmathsandphysics

  • SF Overlord
  • *********
  • Posts: 11271
  • Reputation: 65534
  • Gender: Male
  • Free the exam papers!
Re: Math Heeelppp!!
« Reply #11 on: November 08, 2009, 05:28:46 pm »
c)%error =(121-115.625)/121*100
dii) steepest when dy/dx greatest or least y=5x/8-x^2/800+50 so dy/dx=5/8-x/400 so greatest when x=0 or 500

Offline al noor

  • SF Citizen
  • ***
  • Posts: 158
  • Reputation: 33
Re: Math Heeelppp!!
« Reply #12 on: November 08, 2009, 05:30:37 pm »
Here you go! For the first page :)

Dear astarmathsandphysics,

Would you mind helping me check it as well, sir? xD Just in case I make mistakes. By the way, the equation is fractional :)

Thankyoouu soo muccchh :)

Offline Tyserius

  • Actuary Wannabe
  • SF Geek
  • ****
  • Posts: 318
  • Reputation: 383
  • Gender: Male
  • You are who you choose to become
Re: Math Heeelppp!!
« Reply #13 on: November 08, 2009, 05:31:30 pm »
Thankyoouu soo muccchh :)

You're most welcome. Hope it helps :)
Take it easy and go slow and steady.

Offline al noor

  • SF Citizen
  • ***
  • Posts: 158
  • Reputation: 33
Re: Math Heeelppp!!
« Reply #14 on: November 08, 2009, 05:42:02 pm »
Thankyoouu soo muccchh :)

can u help me with these also?
It will be a great pleasure ;)