Answer:
-5
Step-by-step explanation:
The parabolas equation is
(y - k)^2 = 4p(x - h)
Where h,k is the vertex
Substituting the vertex ad (2,-4)
(y - -4)^2 = 4p(x - 2)
(y +4)^2 = 4p(x - 2)
We need to find p from the other point they give us (-3,-3)
(-3 +4)^2 = 4p(-3 - 2)
1^2 = 4p (-5)
1 = -20p
Divide by -20
1/-20 = -20p/-20
-1/20 = p
Substituting back into the equation
(y +4)^2 = 4(-1/20)(x - 2)
Simplifying
(y +4)^2 = (-1/5)(x - 2)
FOILing
y^2 +8y +16 = -1/5x +2/5
Multiply by 5
5y^2 +40y +80 = -x +2
Subtract 2
5y^2 +40y +80-2 = -x +2-2
5y^2 +40y +78 = -x
Multiply by -1
-5y^2 -40y -78 = x
The coefficient of y^2 is -5
