Volume by Integration; (2 Viewers)

[Finx]

Find the volume of the solid formed when the curve y=(x+5)² is rotated about the y-axis from y=1 to y=4.

So far I've got;

V = pi∫x²dy

y = (x+5)²
y = x² + 10x + 25
x² = y - 10x - 25

I'm stuck here - what do I do with the single x term?

Thanks in advance

 

[lolokay]

you have: y = (x+5)²
what would be a better way to get x on its own than expanding?

 

[Finx]

Sweet, thanks ^_^.

/facepalm

 

[cutemouse]

you have: y = (x+5)²
what would be a better way to get x on its own than expanding?

Pascal's triangle?


..... xD kidding