填空题设曲线y=4-x2(x≥0)与x轴，y轴及直线x=4所围成的平面图形为D(如<br/> 图1—3—2中阴影部分所示)．<br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20240620/14288536_0.png"><br/> 图1—3—1<br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20240620/14288536_0_1.png"><br/> 图1—3—2<br/> ①求D的面积S；<br/> ②求图中x轴上方的阴影部分绕y轴旋转一周所得旋转体的体积Vy．