[填空题]
The following diagrammhs7zh a-38z vm g z9s* w8czvxt,)xi5 shows the graph of the function $f(x)=\frac{b}{a} \sqrt{a^{2}-x^{2}}$
Find an expression, in terms of a and b , for the volume of the solid formed by rotating the curve $360^{\circ} $ about the x -axis.
we get V=$\frac{x{\pi}ab^2}{y}$;x= ,y= .
