Identify the following surfaces as an elliptical paraboloid, hyperbolic paraboloid, a hyperboloid of one sheet, a hyperboloid of two sheets, a cone, a circular cylinder, an elliptical cylinder, or a parabolic cylinder, and identify the axis of symmetry as the x-axis, the y-axis, or the z-axis.

a. ? elliptical paraboloid hyperbolic paraboloid hyperboloid of one sheet hyperboloid of two sheets cone circular cylinder elliptical cylinder parabolic cylinder   ? along the x-axis along the y-axis along the z-axis   $9 x^2 + 6 y^2 - z = 0$

b. ? elliptical paraboloid hyperbolic paraboloid hyperboloid of one sheet hyperboloid of two sheets cone circular cylinder elliptical cylinder parabolic cylinder   ? along the x-axis along the y-axis along the z-axis   $-3 x^2 - 6 y^2 + z^2 = 1$

c. ? elliptical paraboloid hyperbolic paraboloid hyperboloid of one sheet hyperboloid of two sheets cone circular cylinder elliptical cylinder parabolic cylinder   ? along the x-axis along the y-axis along the z-axis   $-3 x^2 + 8 y^2 - z^2 = 0$

d. ? elliptical paraboloid hyperbolic paraboloid hyperboloid of one sheet hyperboloid of two sheets cone circular cylinder elliptical cylinder parabolic cylinder   ? along the x-axis along the y-axis along the z-axis   $8 y^2 - 9x^2 - 3 z^2 + 1 = 0$

e. ? elliptical paraboloid hyperbolic paraboloid hyperboloid of one sheet hyperboloid of two sheets cone circular cylinder elliptical cylinder parabolic cylinder   ? along the x-axis along the y-axis along the z-axis   $3 y^2 + 3 z^2 = 1$