[问答题]
Consider the function f(x) defin
bdn0j7w4s2me ed by f(x)=12-1
t: w:07hlggz .tmcf y42 sin x , for $0 \leq x \leq 3 \pi$ . The following diagram shows the graph of y=f(x) .
The graph of f touches the x -axis at points A and B , as shown. The shaded region is enclosed by the graph of y=f(x) and the x -axis, between the points A and B .
1. Find the x -coordinate of A and B .
2. Show that the area of the shaded region is 24 $\pi$ .
The following right cone has a total surface area of 24 $\pi$ , equal to the shaded area in the previous diagram.
The cone has a base radius of 3 , height h , and slant height l .
3 . Find the value of l .
4. Hence, find the volume of the cone.
