Question

please help!!

Functions 1 and 2 are shown below:

Function 1: f(x) = −3x2 + 2
A graph of a parabola with x intercepts of negative 0.5, 0 and 2, 0 and a vertex of 0.5, 4 is shown.

Which function has a larger maximum?

http://learn.flvs.net/webdav/assessment_images/educator_algebraI_v20/09_01_17.gif
function 2^^

Answer 1

it doesn't let to open the link..

Answer 2

oh okay hold on

Answer 3

ok... so for function 1, where is the vertex..?

the parabola is concave down..?

Answer 4

I'm honestly not sure, I'm confused on how to do any of that

Answer 5

have you learnt about the line of symmetry or the vertex equation for a parabola..?

Answer 6

yeah but it confuses me

Answer 7

ok... so the max value is on the line of symmetry.

the max value is also the y-value in the vertex...

so for function 1

line of symmetry

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

so in function 1, a = -3 and b = 0

what is the equation of the line of symmetry, just substitute the values..?

Answer 8

it is -6??

Answer 9

wait i mean 0

Answer 10

correct, the x value in the vertex is x = 0

now substitute that into the original equation,

what is the y value..?

Answer 11

2?

Answer 12

@campbell_st

Answer 13

great, so function 1 has a vertex at (0, 2)

function 2 has a vertex at (0.5, 4)

compare the y values in the vertex to see which graph is higher

Answer 14

so function 2 right

Answer 15

correct...

Answer 16

thanks!