SOLUTION: Write the equation of each parabola described. 1.) Vertex at (2,5) Focus at (2,-3) 2.) Diretrix: x= 3/4 Focus: (5/9, -3)

Algebra ->  Length-and-distance -> SOLUTION: Write the equation of each parabola described. 1.) Vertex at (2,5) Focus at (2,-3) 2.) Diretrix: x= 3/4 Focus: (5/9, -3)      Log On


   

Question 1104254: Write the equation of each parabola described.
1.) Vertex at (2,5) Focus at (2,-3)
2.) Diretrix: x= 3/4 Focus: (5/9, -3)
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
You could try to use the formula, in your example number 2 in the form
-4p%28x-h%29=%28y-k%29%5E2 for vertex (h,k), and p the distance from vertex to either focus or directrix.

Vertex for #2 is (47/72, -3), and p=abs%285%2F9-47%2F72%29=7%2F72.

The basic formula will then give you highlight_green%28-4%287%2F72%29%28x-47%2F72%29=%28y%2B3%29%5E2%29, which you can simplify on the left hand side.

You really should learn how to use the parabola definition to derive the equations, and also learn to use the resulting formula.