SOLUTION: What would the focus and directrix of the equation y=3x^2 -5x^2 +3?
I have simplified it to y= -2x^2 +3 but i don't know what to do from there.
Algebra ->
Quadratic-relations-and-conic-sections
-> SOLUTION: What would the focus and directrix of the equation y=3x^2 -5x^2 +3?
I have simplified it to y= -2x^2 +3 but i don't know what to do from there.
Log On
Question 599369: What would the focus and directrix of the equation y=3x^2 -5x^2 +3?
I have simplified it to y= -2x^2 +3 but i don't know what to do from there. Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! What would the focus and directrix of the equation y=3x^2 -5x^2 +3?
----
Form: (x-h)^2 = 4p(y-k)
----------
Your Problem:
y = -2x^2+3
y-3 = -2(x-0)^2
-----
4p = -2
p = -1/2
----------
Vertex: (0,3)
The parabola opens down so focus is at: (0,3-(1/2) = (0,5/2)
Directrix is y = 3-(-1/2) = 7/2
====================
====================
Cheers,
Stan H.
====================
(