SOLUTION: Dear Ma'am/Sir, Good day! Kindly help me with this mathematical problem, I do not know much about analytic geometry, please help me. Here it goes: The endpoints

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Dear Ma'am/Sir, Good day! Kindly help me with this mathematical problem, I do not know much about analytic geometry, please help me. Here it goes: The endpoints      Log On


   



Question 812895: Dear Ma'am/Sir,
Good day! Kindly help me with this mathematical problem, I do not know much about analytic geometry, please help me.
Here it goes:
The endpoints of the latus rectum of a parabola are (5,k), and (-5,k). If the vertex of the parabola is at the origin, and the parabola opens downward, find
a) the value of k
b) an equation of the parabola
Thank you so much!

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi
endpoints of the latus rectum of a parabola are (5,k), and (-5,k).
vertex of the parabola is at the origin, and the parabola opens downward
the vertex form of a Parabola opening up(a>0) or down(a<0), y=a%28x-h%29%5E2+%2Bk
where(h,k) is the vertex and x = h is the Line of Symmetry
The standard form is %28x+-h%29%5E2+=+4p%28y+-k%29, where the focus is (h,k + p)
%28x+-0%29%5E2+=+4p%28y+-0%29,
4p = 10, (length of latus rectum is 4p Focal point is ( 0,-10/4 )
-x%5E2+=+10y