Question

Find the vertex of the parabola
f(x)=-4x^(2)+40x-93

Answer 1

I tried using the quadratic formula but im just getting (-40 plusminus sqrt112)/-8

Answer 2

\[\left( -\frac{ b }{ 2a },f \left( -\frac{ b }{ 2a } \right) \right)\]

Answer 3

Would I make it -40/8 or -40/-8?

Answer 4

\[-\frac{ b }{ 2a }=-\left( \frac{ 40 }{ 2\cdot \left( -4 \right) } \right)=\frac{ 40 }{ 8 }=5\]

Answer 5

That makes more sense. So then I'd have for my y it'd be 27?

Answer 6

no

Answer 7

(5,7) isn't it

Answer 8

-4(5)^2+40(5)-93 = -4(25)+40(5)-93 = -100 + 200 - 93 = 7

so yes marigirl

Answer 9

Oops sorry. Thanks.

Answer 10

now worries rrey! you never need to apologize for effort... only lack of it!

Answer 11

no, not now

Answer 12

as in no worries

Answer 13

as in, it's okay