How do I find an equation of a parabola that has a vertex of
How do I find an equation of a parabola that has a vertex of (-1,0) and focus of (plus/minus5,0)?
Solution
vertex of (-1,0) and focus of (5,0)
distance fromm focus to vertex , a=[(-1-5)2+(0-0)2] =6
general equation of parabola opened to right is (y-k)2=4a(x-h)
vertex (h,k)=(-1,0),a =6
(y-0)2=4*6(x-(-1))
y2=24(x+1)
y2=24x+24
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vertex of (-1,0) and focus of (-5,0)
distance fromm focus to vertex , a=[(-1+5)2+(0-0)2] =4
general equation of parabola opened to left is (y-k)2=-4a(x-h)
vertex (h,k)=(-1,0),a =4
(y-0)2=-4*4(x-(-1))
y2=-16(x+1)
y2=-16x-16
