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Hi!

 

I'm having trouble with an integration problem.

 

 

2π × integral between 0 and 6 of (0.02x^3-0.39x^2+1.77x+0.18) × (sqrt(0.0036x^4-0.0936x^3+0.8208x^2-2.7612x+4.1329)) dx

 

Does anyone know how to solve it or have any suggestions?

 

Thanks heaps!

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Hi!

 

I'm having trouble with an integration problem.

 

 

2π × integral between 0 and 6 of (0.02x^3-0.39x^2+1.77x+0.18) × (sqrt(0.0036x^4-0.0936x^3+0.8208x^2-2.7612x+4.1329)) dx

 

Does anyone know how to solve it or have any suggestions?

 

Thanks heaps!

 

The numbers in this integral seem to be very irregular, so I don't think you have to solve this by hand. Using my Ti-84, the answer is: 82.6

Here are the workings:

 

post-115475-0-46872500-1430820110.png, post-115475-0-59185200-1430820115.png, post-115475-0-67872200-1430820129.png

 

Hope this helps :)

Edited by Vioh
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Hi!

 

I'm having trouble with an integration problem.

 

 

2π × integral between 0 and 6 of (0.02x^3-0.39x^2+1.77x+0.18) × (sqrt(0.0036x^4-0.0936x^3+0.8208x^2-2.7612x+4.1329)) dx

 

Does anyone know how to solve it or have any suggestions?

 

Thanks heaps!

 

The numbers in this integral seem to be very irregular, so I don't think you have to solve this by hand. Using my Ti-84, the answer is: 82.6

Here are the workings:

 

attachicon.gifa1.png, attachicon.gifa2.png, attachicon.gifa3.png

 

Hope this helps :)

 

This helps thanks! But I also need to show the working for this problem. Would you know how to do this?

 

Thank you so much!

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This helps thanks! But I also need to show the working for this problem. Would you know how to do this?

 

If this is part of your IA or something similar, then the photographs of the calculator themselves can be used to show the working for the problem. On the other hand, if this problem is in the IB exam for example, then you don't really need to show any workings at all. It is enough to just say: Using the GDC (graphic display calculator), the answer to this integral is 82.6 :)

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This helps thanks! But I also need to show the working for this problem. Would you know how to do this?

 

If this is part of your IA or something similar, then the photographs of the calculator themselves can be used to show the working for the problem. On the other hand, if this problem is in the IB exam for example, then you don't really need to show any workings at all. It is enough to just say: Using the GDC (graphic display calculator), the answer to this integral is 82.6 :)

 

Ok thank you for all your help :)

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I'll cast a shade of doubt... when I copied the integral to Wolfram Alpha, it showed the result as 13.1478

http://www.wolframalpha.com/input/?i=integrate+%280.02x%5E3-0.39x%5E2%2B1.77x%2B0.18%29*%28sqrt%280.0036x%5E4-0.0936x%5E3%2B0.8208x%5E2-2.7612x%2B4.1329%29%29+dx+from+x%3D0+to+6

 

Edit: my bad, forgot to multiply it by 2*pi, it is 82.61 in the end.

Edited by Slovakov
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oh, I think that's because you forgot to put the 2pi in front of it. Notice that 2pi * 13.1478 = 82.6 :)

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