Question

The equation f(x) = 3x2 − 24x + 8 represents a parabola. What is the vertex of the parabola?

(−4, 152)

(4, −40)

(−3, 107)

(3, −37)

Answer 1

i dont know what a parabola is

Answer 2

@DanJS

Answer 3

https://www.khanacademy.org/math/algebra/quadratics/solving_graphing_quadratics/v/finding-the-vertex-of-a-parabola-example

Answer 4

a symmetrical open plane curve formed by the intersection of a cone with a plane parallel to its side. The path of a projectile under the influence of gravity ideally follows a curve of this shape.

Answer 5

you could complete the square to make the vertex equation form

Answer 6

ok i know how to complete the sqaure

Answer 7

8, 1\3

Answer 8

y = a(x-h)^2 + k

vertex at (h,k)

Answer 9

huh?

Answer 10

ive never heard of that

Answer 11

this is so confusing

Answer 12

the video that was linked is good

Answer 13

ok ill watch it real quick brb

Answer 14

If you havent done anything else yet , just plug in the numbers to that

Answer 15

yea i dont get it

Answer 16

\[y = ax^2 + bx +c\]

x coordinate of the vertex will be
\[\frac{ -b }{ 2a }\]

Answer 17

b = -24
a = 3

Answer 18

so divide that?

Answer 19

yes, just calculate it, put in the , a and b, values

Answer 20

ok ill do that now

Answer 21

i got -8b\a

Answer 22

X - Coordinate of Vertex

\[\frac{ -b }{ 2a } = \frac{ -(-24) }{ 2*3 } = \frac{ 24 }{ 6 } = 4\]

Answer 23

i have to leave in like 3 minutes should i just guess??

Answer 24

wait its b ???

Answer 25

The X coordinate for the vertex is -b/(2a) = 4

To get the Y-Coordinate for that X value, plug in x=4 into the original
y = 3x^2 - 24x + 8

Answer 26

well you dont have to do that, if the X coordinate is 4, there is only one choice

Answer 27

i just turned it in, b is right :)

Answer 28

yea

just have to remember the \[\frac{ -b }{ 2a }\]

for the x-coordinate of the vertex