Analysis
  Artist
Topics: 72
Replies: 6282
Registered: 16.Mar.03 |
double post...  |
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xTr1m
 Administrator
Topics: 106
Replies: 4441
Registered: 11.Oct.03 |
Analysis wrote on 01 Dec. (23:31) :
if X = 1, the following should work:
1/Y = Y/Z --> Z(1/Y) = Y
1 = Y + Z --> Z = 1 - Y
Z(1/Y) = Y ---> Y = (1 - Y)(1/Y) --> Y = 1/Y - 1 --> Y2 = 0
Hence --> Y = 0, X = 1 and Z = 1
(basically, every answer is right as long as X = Z and Y = 0)
Don't take yourself to serious |
Completely wrong!!
x/y must be equal to y/z.
for y=0, x=1, z=1, you assume that 1/0=0/1 which leads to an error. Reconsider 
->)>- Victor Vergara (Awezoom) - Beyond the Heart (685 hits) -<(<- played live by me! 
I don't own a tube amp! HA! HA! |
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xTr1m
Administrator
Topics: 106
Replies: 4441
Registered: 11.Oct.03 |
cadra wrote on 02 Dec. (0:44) :
N.D. wrote on 02 Dec. (0:30) :
Have you guys ever heard of "the golden section"? It's what is commonly used in webdesign and might bring you closer to the solution 
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yeah.. something involving the square root of 5... right?
oh wait. check this. x/y=y/z and x=y+z. i'm gonna assume z=1 for now.
(y+z)/y=y/z
(y+1)/y=y
y+1=y^2
y^2-y-1=0
D=(-1)^2-4*1*(-1)=5
this is looking better.
y=(-b-V(D))/2a or y=(-b+V(D))/2a
y=(1-V(5))/2 or y=(1+V(5))/2
y=-0.618033989
or y=1.618033989
assuming lengths can't be negative.
to get the answer to the initial problem:
my_x=my_y+my_z=1.618+1=2.618
real_x=1
so divide everything i said by 2.618; you get:
x=1
y=1.618/2.618=0.618 (whaddyaknow?)
z=1/2.618=0.382
and yes, 0.618+0.382=1
*sigh*
pr0n |
CONGRATS  , that's correct!
->)>- Victor Vergara (Awezoom) - Beyond the Heart (685 hits) -<(<- played live by me!
I don't own a tube amp! HA! HA! |
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Analysis
Artist
Topics: 72
Replies: 6282
Registered: 16.Mar.03 |
uhm, we already knew what was the best option 
Anyone that can solve my problem?
Don't take yourself to serious |
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Nygen Dale
Staff / Moderator
Topics: 68
Replies: 3617
Registered: 21.Jun.03 |
Analysis wrote on 02 Dec. (1:14) :
Alright, that should be clear.
The question is, how big has X got to be, so that the surface of the rectangle in the middle is half the size of the surface of the total rectangle?
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Surface of the big rectangle:
30 * 40 = 1200
Surface of the little rectangle:
600 (duh!)
Which leads to the following:
30x * 40x = 600
1200x^2 = 600
x^2 = 1/2
x = sqrt(1/2)
That means the length of the little rectangle is:
40 * sqrt(1/2)
And the height is:
30 * sqrt(1/2)
So the big X would have to be:
40 - [40 * sqrt(1/2)] / 2
20 - [20 * sqrt(1/2)]
~ 5,86
www.nd-music.com |
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Link
Artist
Topics: 1
Replies: 85
Registered: 17.Jul.04 |
x= - [(600 - sqrt(720000))/sqrt(1800]
~ 5,86
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Analysis
Artist
Topics: 72
Replies: 6282
Registered: 16.Mar.03 |
That's not correct. I can show that it isn't correct, but then I'd be revealing how you should work on this problem so i'll explain it later...
Don't take yourself to serious |
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kazakore
Artist
Topics: 2
Replies: 29
Registered: 02.Dec.05 |
Answer is 5.86!
This gives you a height of 21.21 and a width of 28.28.
21.21 * 28.28 = 599.82 (as I have been rounding up. Used .707 instead of (1)/(2^(1/2)) )
(40 - 28.28) / 2 = 5.86
No error in there. Unless your rectangle doesn't keep a 4:3 ratio 
Areas are easy. If you half the area each length is going to be 1/root2, third area each length is 1/root3, quarter 1/root4 ad infinum. If we were talking volumes it would be cube-roots.
Come on then matey, come and correct us |
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g
 Member
Topics: 10
Replies: 2037
Registered: 03.Jan.03 |
(40-2x)(30-2x)=40*30/2=600
(20-x)(15-x)=150
300-20x-15x+x^2=150
x^2-35x+150=0
x=(35/2)+-sqrt((35/2)^2-150)
x=(35/2)+-sqrt(1225/4-150)
x=(35/2)+-sqrt(625/4)
x=(35/2)+-25/2
(x1=60/2=30)
x2=10/2=5=x
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g
Member
Topics: 10
Replies: 2037
Registered: 03.Jan.03 |
kazakore wrote on 03 Dec. (1:27) :
No error in there. Unless your rectangle doesn't keep a 4:3 ratio |
I assumed it didn't... Which made it a bit too simple I guess. |
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