Asked by Andrea
                Find b and c so that y=-1x^2+bx+c has vertex (-5,-4). Please help ASAP I'm having a really hard time on this question!!!
            
            
        Answers
                    Answered by
            clement
            
    parabola equation y=ax²+bx+c
the x- coordinate is -b/2a
so for
y=-x²+bx+c
ax²+bx+c=-x²+bx+c
a=-1
b/2(1)=-5
b=-10
hence you have the equation to be
y=-x²-10x+c
x²+10x-c=-y
(2)²+10(2)-c=4
4+20-c=4
24-c=4
-c=4-24
c=20
    
the x- coordinate is -b/2a
so for
y=-x²+bx+c
ax²+bx+c=-x²+bx+c
a=-1
b/2(1)=-5
b=-10
hence you have the equation to be
y=-x²-10x+c
x²+10x-c=-y
(2)²+10(2)-c=4
4+20-c=4
24-c=4
-c=4-24
c=20
                    Answered by
            clement
            
    do you think you can help me check my question
    
                    Answered by
            clement
            
    i think i made a typo b=10
not -10
because of the negative value of a
that shouldn't be a problem right
the ideal is the same,so you do the correction
    
not -10
because of the negative value of a
that shouldn't be a problem right
the ideal is the same,so you do the correction
                    Answered by
            oobleck
            
    You want y=-1x^2+bx+c with vertex at (-5,-4)
The vertex at (-5,-4) means that
y = a(x+5)^2 - 4
So now you have
ax^2 + 10ax + 21 = -x^2+bx+c
(a,b,c) = (-1,10,21)
    
The vertex at (-5,-4) means that
y = a(x+5)^2 - 4
So now you have
ax^2 + 10ax + 21 = -x^2+bx+c
(a,b,c) = (-1,10,21)
                                                    There are no AI answers yet. The ability to request AI answers is coming soon!
                                            
                Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.