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# P3 Question (its in 2 hrs :() watch

1. This question is also from the P3 June 2003 paper, question 5

there's a curve of y = x(sin x)^1/2

graph has a maximum point at A..

a) Show that x-coordinate of point A satisfies equation 2tanx + x =0
- thats alright but question b

b)
The finit region enclosed by the curve and the x axis is shaded in fig 1 (simply the area below the curve)
A solid body S is generated by rotating this region around 2(pi) radians about x-axis.. Find the exact value of the volume S

My answer is (Pi)^2 - 4.. (or 5.87 to 3 SF)..

Can please anyone check if that's correct?
2. (Original post by hitmannq8)
This question is also from the P3 June 2003 paper, question 5

there's a curve of y = x(sin x)^1/2

graph has a maximum point at A..

a) Show that x-coordinate of point A satisfies equation 2tanx + x =0
- thats alright but question b

b)
The finit region enclosed by the curve and the x axis is shaded in fig 1 (simply the area below the curve)
A solid body S is generated by rotating this region around 2(pi) radians about x-axis.. Find the exact value of the volume S

My answer is (Pi)^2 - 4.. (or 5.87 to 3 SF)..

Can please anyone check if that's correct?
you did the integration by parts right, but remember to multiply by 'pi' when working out volumes, i.e. V = pi [INT y^2 dx]
so the answer is pi ( pi^2 - 4)
3. (Original post by hitmannq8)
This question is also from the P3 June 2003 paper, question 5

there's a curve of y = x(sin x)^1/2

graph has a maximum point at A..

a) Show that x-coordinate of point A satisfies equation 2tanx + x =0
- thats alright but question b

b)
The finit region enclosed by the curve and the x axis is shaded in fig 1 (simply the area below the curve)
A solid body S is generated by rotating this region around 2(pi) radians about x-axis.. Find the exact value of the volume S

My answer is (Pi)^2 - 4.. (or 5.87 to 3 SF)..

Can please anyone check if that's correct?

use product rule and chain rule to get.
dy/dx = (sinx)^1/2 + 1/2x(sinx)^-1/2.cosx

um not sure to go on from there.
4. Thanx mockel!

oww I hope i dont do a lazy mistake like forgetting that Pi .. does anyone know where can i get Edexcel past paper mark schemes online?
5. (Original post by hitmannq8)
Thanx mockel!

oww I hope i dont do a lazy mistake like forgetting that Pi .. does anyone know where can i get Edexcel past paper mark schemes online?
Found one online:
http://www.risctex.freeuk.com/
6. (Original post by meepmeep)
Found one online:
http://www.risctex.freeuk.com/
trry www.ajimal.com for unofficial mark schemes

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