- #1
Lily Rose
- 5
- 0
Hi. I understand how to solve surface Area using integration when it is to be revolved about the x or y axis. But when the axis is not x or y I have a difficult time solving it. Please help me. Here is the equation
sqrt(x+1) rotated at x=-1 and y=5.
the bounds are 1 to 5.
since y=sqrt(x+1)
x = y^2 -1
I solved for x=-1 and I got ∫ (from 1 to 5) 2pi ((y^2 -1) +1) √(1+4y) dy
and for y=5 ∫ (from 1 to 5) 2pi ((√x+1)+5) √(1+ [itex]\frac{1}{4x+4}[/itex])
pls help me. I really do understand on how to rotate it about the x or y axis. I tried searching online for some tutorials but I can't find any.
sqrt(x+1) rotated at x=-1 and y=5.
the bounds are 1 to 5.
since y=sqrt(x+1)
x = y^2 -1
I solved for x=-1 and I got ∫ (from 1 to 5) 2pi ((y^2 -1) +1) √(1+4y) dy
and for y=5 ∫ (from 1 to 5) 2pi ((√x+1)+5) √(1+ [itex]\frac{1}{4x+4}[/itex])
pls help me. I really do understand on how to rotate it about the x or y axis. I tried searching online for some tutorials but I can't find any.