Calculate the width of the gutter where the depth is 6cms

  • Thread starter Paulo2014
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1. The problem statement, all variables and given/known data
The cross-section of a gutter can be represented by the quadratic:
y=4/11x^2-4x+11 where x and y are measurements in cm. Calculate the width of the gutter where the depth is 6cms.


2. Relevant equations



3. The attempt at a solution
my answer was 1.26cm or 12.6mm but i'm pretty sure thats wrong so could someone please explain how to work it out?
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution
 
308
0
What did you try?
 

HallsofIvy

Science Advisor
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1. The problem statement, all variables and given/known data
The cross-section of a gutter can be represented by the quadratic:
y=4/11x^2-4x+11 where x and y are measurements in cm. Calculate the width of the gutter where the depth is 6cms.
It's impossible to say if you won't tells us which of x, y is the width and which is the depth! I might guess that x is twice the width and y the depth, so that you need to solve the equation (4/11)x^2- 4x+ 11= 6. My guess is partly based on the fact that if x is the depth, you would only need to evaluate that (4/11)(6)^2- 4(6)+ 11 and that is too easy!


2. Relevant equations



3. The attempt at a solution
my answer was 1.26cm or 12.6mm but i'm pretty sure thats wrong so could someone please explain how to work it out?
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution
 
sorry guys... x is width and y is depth
 

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