Fill in the missing term so that the quadratic equation has a graph that opens up, with a vertex of
(– 3, – 25), and x intercepts at x = -8 and x = 2. (Do not include the negative sign in your answer.)

y = x2 + 6x − ___

Question

Fill in the missing term so that the quadratic equation has a graph that opens up, with a vertex of 
(– 3, – 25), and x intercepts at x = -8 and x = 2. (Do not include the negative sign in your answer.)

y = x2 + 6x −  ___

anonymous · Answer

what ?

anonymous · Answer

you know it looks like 
$$a(x+8)(x-2)=a(x^2+6x-16)$$ so you know the constant is -16

anonymous · Answer

i said TMI because the first coordinate is an unnecessary piece of information

anonymous · Answer

ohkay thanks and are you sure that is the correct answer ?

anonymous · Answer

you are asked to enter it without the minus sign, so put in "16"

anonymous · Answer

ok thanks

anonymous · Answer

the point is if the vertex was not (-3,-25) there would be no solution to this, so it is a rather dumb question.  you are given more information that the poor quadratic can handle.  you might want to mention this to your math teacher

anonymous · Answer

since the vertex is (-3,-25) you know it looks like 
$$y=a(x+3)^2-25$$ and now all you need is one more point to find out that a = 1
in other words: the vertex and one other point would give the answer!