By setting one variable equal to a constant (either or for some constant ), find a plane that intersects the graph of in:
a.
?
x = c
y = c
z = c
a Hyperbola.
b.
?
x = c
y = c
z = c
a Parabola opening downward.
c.
?
x = c
y = c
z = c
a Parabola opening upward.
d.
?
x = c
y = c
z = c
a Pair of intersecting lines.
For what value of the constant c do you get a pair of intersecting lines?
In order to get credit for this problem all answers must be correct.