Why is that when i am trying to use the shell method for this problem: y=5x+6 and y=x^2, rotated about the x axis, i have to break it up into two integrals.

Question

Why is that when i  am trying to use the shell method for this problem: y=5x+6 and y=x^2, rotated about the x axis, i have to break it up into two integrals.

amistre64 · Answer

well, lets draw it :)

amistre64 · Answer

|dw:1316890480442:dw|

amistre64 · Answer

since you have a odd spot that you have to account for, its best to do it in parts

amistre64 · Answer

|dw:1316890571158:dw|

anonymous · Answer

ah, i see that small portion below y=1

amistre64 · Answer

the equations for the area change at that point :)

anonymous · Answer

so the radius of that would still be y

amistre64 · Answer

correct, the radius of the shell doesnt change; just the equations that define the area

anonymous · Answer

but what would be the heigh, woudl it just be sqrtx-0

amistre64 · Answer

lets turn this to see it in a normal view point