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Edexcel A2 C4 Mathematics June 2015 - Official Thread

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Original post by SCAR H
whats; C1 65 C2 63?

83 and 86
Original post by 1 8 13 20 42
83 and 86


Thanks :smile:
Original post by 1 8 13 20 42
95-97 and 82


Damn its gonna be close, cherrs
Original post by ArkadiusBear
Okay good because i got that correct, and the volume of the cone correct, but for some reason I took the volume of the cone away from the curve incorrectly, how many marks do you think is lost there?


I'm doing this paper as practice and I really want to know why u take take the area of the cone away from the area found (40pi/ln3)..
Original post by Rubyx
I'm doing this paper as practice and I really want to know why u take take the area of the cone away from the area found (40pi/ln3)..


The volume of revolution is calculated between the x co-ordinates 0 and P.
https://gyazo.com/387da5099183f1a2af2b7bebb1a4b036
As this photo shows, the cross-section of the shape formed can be obtained by drawing vertical lines down at the x co-ordinates of the function.
The 2d cross-sectopm obtained for question 8b would contain the 2d shape you're trying to find the volume of, plus an additional triangle.
When you rotate the cross-section shape, you then would get the volume you are trying to obtain plus a cone (the rotated triangle). Therefore, to find the volume of the shape, you will have to subtract the volume of the cone.
Original post by cerlohee
The volume of revolution is calculated between the x co-ordinates 0 and P.
https://gyazo.com/387da5099183f1a2af2b7bebb1a4b036
As this photo shows, the cross-section of the shape formed can be obtained by drawing vertical lines down at the x co-ordinates of the function.
The 2d cross-sectopm obtained for question 8b would contain the 2d shape you're trying to find the volume of, plus an additional triangle.
When you rotate the cross-section shape, you then would get the volume you are trying to obtain plus a cone (the rotated triangle). Therefore, to find the volume of the shape, you will have to subtract the volume of the cone.


Do you really.
Some crazy ****.
I think its fake.


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