sketch cylinder that has directrix curve y^2-x^2=1 and ruling parallel to the z axis.

Question

anonymous · Answer

what's a directrix curve? :(

anonymous · Answer

thats on the x y axis?

dumbcow · Answer

wait im wrong ...i found what you need though http://hardycalculus.com/calcindex/IE_cylinder.htm

anonymous · Answer

i have no idea what this means lol

anonymous · Answer

none of these have a -x :(

dumbcow · Answer

yeah it doesn't show a hyperbola :|
i've never come across these before...maybe i will learn something today

anonymous · Answer

._.

anonymous · Answer

lol this is the only test i don't have the answers to xD

anonymous · Answer

k ima come back to this question... lol you want me to tag you if i ask it again? :o

dumbcow · Answer

sure, i'll see if i can figure it out in next couple min

anonymous · Answer

ooohhh okay!! thank you :D :D

dumbcow · Answer

@itzmashy , ok looks like i was correct the first time
the graph of the hyperbola is in xy plane, then goes straight up along z-axis
so the shape of cylinder is hyperbolic

the directrix curve describes the shape of the base of the cylinder

dumbcow · Answer

|dw:1337156457448:dw|
sorry can't draw very well