1. Find the focus and directrix of the equation. (y+3)^2 =8(x-2)
I got the focus is (4,-3) and the directrix is x=0
is this right?
2. Find the vertices and foci of this ellipse. x^2/49 +y2/9=1
For vertices I got: (7,0) and (-7,0) but it said I was wrong. and for Foci I got (2 root 10, 0) and (-2 root 10,0) I don't know if the foci is right but I dont know how to put in square roots on webassign.
3. A hall 100 feet in length is to be designed as a whispering gallery. If the foci are located 22 feet from the center, how high will the ceiling be at the center?
No idea.
4. Find an equation for the hyperbola described. Foci at (-5,0) and (5,0); vertex at (3,0)
I got (x^2)/4 - (y^2)/3 =1 but it said I was wrong I don't understand.
5. Identify the conic x^2 +2xy+3y^2-2x+4y+10 = 0
I said none of these, but I'm wrong.
6. r = 8/ 4-2sintheta
i said directrix is 1/2 units below the pole and it said wrong.
also, how do you know if the directrix is parallel or perpindicular?
7. Lastly
r= 4/ 2-3sintheta i said directrix is 1.5 units below the pole it said wrong
** NOTE: some of these problems may be webassign formatting but maybe not!