[填空题]
The following diagrax hiawh0nyt wy w:70+.2o1ycl f7mp2ymp7*czk on r+l jj41v9o 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= .
