jennilalala Group Title Use the shell method to ﬁnd the volume of the solid generated by revolving about the y-axis. x=sqrt(9-x^2) and x=0 one year ago one year ago

1. Callisto

The equation should be$y =\sqrt{9-x^2}$?

2. Callisto

Assume the equation of the line is $$y=\sqrt{9-x^2}$$ Domain of the function: [-3, 3] So, integrate from x=0 to x=3 $V=\int_0^3 2\pi xf(x) dx = 2\pi \int_0^3 x\sqrt{9-x^2} dx=...$

if revolving about the y-axis, the integration should forward dy so, v=pi*int((f(y))^2 dy [y1,y2] with y1 and y2 are under interval and up interval respectively

4. Callisto

Shell method.... about y-axis => dx See this: http://mathworld.wolfram.com/MethodofShells.html

5. Callisto

@RadEn Yours is disc method, I think