[填空题]
Consider the ellipse defined z1cy vn7,an) )zzzd)j by the m:tm-4ybtz3 u ojwj 5,equation $x^{2}+3 y^{2}=12$ .
1. Find the equation of the normal to the ellipse at the point P(3,1) . y =
2. Find the volume of the solid formed when the region bounded by the ellipse, the x -axis for $x \geq 0$ and the y -axis for $y \geq 0$ is rotated through $2 \pi$ about the y -axis.
