Question

fine b and c so that y=7x^2+bx+c has a vertex (4,-10)

Answer 1

well the line of symmetry can be found using

\[x = \frac{-b}{2a}\]

from the vertex you know the like of symmetry is x = 4 and from the equation you know a = 7

so you have the equation

\[4 = \frac{-b}{2 \times 7}\]

solve for b.

now substitute b into the original equation...

to find c you know the vertex lies on the parabola. So substitute x = 4 and y = -10 into the equation and solve for c.

hope it helps