Q 4b - Volumes (1 Viewer)

[casomerville]

Did anyone else get 1/2 units^3.

 

[Riviet]

I THINK I got 2 units³.

 

[Naylyn]

I think thats what I got.

 

[casomerville]

i didn't think you could get an answer bigger than 1 because the max height, depth and width was 1.

 

[zeek]

i got 2 units as well

 

[Riviet]

i didn't think you could get an answer bigger than 1 because the max height, depth and width was 1.

This is a simplified version of what I did: delta V=(2x)² delta y, where 2x is the length of a square
=4x² delta y

.'. V = int (0->1) 4y dy
= 2

 

[gamecw]

edit: actually i got 2 aswell lol

sides of square is 2 m remember so it can be biger than 1

 

[Rax]

Yep 2.

I got pi/15 units cubed for the other one

 

[Bricnic]

Yep 2.

I got pi/15 units cubed for the other one

Awesome! I got that too.. I didn't show mcuh working out, you reckon they'll take marks off? I showed the integral and stuff, but didn't bother with elemental volume or writing sigma notation etc. And here I thought I couldn't do volumes! Yay!

 

[pLuvia]

Yep 2.

I got pi/15 units cubed for the other one

Same same

 

[kobz]

i had 4/3 units^3 as the lenght of the square is 2x^2 and the breath is 2x^2 aswell ( its a square lol)

Volume = integral between 1 n 0 of (4x^4) dy but x^4=y^2

therefore = between 1 n 0 of (4y^2)dy

= 4/3 units^3

 

[kobz]

i had 4/3 units^3 as the lenght of the square is 2x^2 and the breath is 2x^2 aswell ( its a square lol)

Volume = integral between 1 n 0 of (4x^4) dy but x^4=y^2

therefore = between 1 n 0 of (4y^2)dy

= 4/3 units^3

shit just looked at the question...im such an idiot thats wrong lol (thats wat happens when u dnt see maths for a good 2 months)

 

[jctaylor]

Um guys, doesnt the question say "*vertical* cross sections perpendicular the the y-axis", as in, the height of the square would be (1 - y) and the width would be dx??

Which all up makes the Volume 16/15 units ^3

 

[bananasmoothy]

I don't think I wrote units^3 after any of my answers.

 

[DraconisV]

Yep i also got 2 UNITS^3
and for the other pi/15 UNITS^3.
Yippie I got both volumes ones right. Yippie, im happy.

Im happy about volumes, complex and curve sketching. Also conics was alright.
The rest, hmm, like 0 marks. argghh!