Question

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!!!

Answer 1

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

Answer 2

do you think you can help me check my question

Answer 3

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

Answer 4

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)