Question 188602
{{{2y=-x^2-6x-15}}}
:
{{{y=-1/2(x^2+6x+9)-15/2+9/2}}}
:
{{{y=-1/2(x+3)^2-3}}}
:
vertex is at (-3,-3)
:
1/4p=-1/2
:
p=-1/2
:
directrix is at y=-5/2
focus is at (-3,-7/2)
:
distance across parabola is abs value of 4p which equals abs value of 4(-1/2)= 2:
{{{graph(300,300,-10,10,-10,10,(-1/2)(x+3)^2-3)}}}