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Mathematics 8 Online
KyledaGreat:

Consider the following function.

KyledaGreat:

\[p(x) = -x ^{2} + 8x - 12\] Find two points on the graph of the parabola other than the vertex and x-intercepts. A: ( , ) B: ( , )

KyledaGreat:

@vocaloid

AZ:

Just plug in any number for x into the equation and simplify it. That'll be the y-value of that point.

KyledaGreat:

could you show me ?

AZ:

For example, if you plug in x = 1 p(1) = -(1)^2 + 8(1) - 12 1^2 is 1 8 * 1 = 8 p(1) = -1 + 8 - 12 p(1) = -19 so one of the points would be (1, -19)

AZ:

the x-value we chose was 1 and the y-value you get when you plug it in is -19 thus, (1, -19)

KyledaGreat:

ohh okay , so i use -1 ?

KyledaGreat:

p(-1) = -(1)^2 + 8(-1) - 12 is this right ?

KyledaGreat:

P = 21

snowflake0531:

where'd your negative sign go?

KyledaGreat:

I thought -1 would be the next one to use for the second potential point

snowflake0531:

p(-1) = -(1)^2 + 8(-1) - 12 p(-1) = -1 - 8 - 12 p(-1) = -21 (-1,-21) you dropped the negative signs

KyledaGreat:

okay , is the first point correct as it is ?

snowflake0531:

yes

KyledaGreat:

okay thank you

KyledaGreat:

it said incorrect for some reason

snowflake0531:

@az wrote:
For example, if you plug in x = 1 p(1) = -(1)^2 + 8(1) - 12 1^2 is 1 8 * 1 = 8 p(1) = -1 + 8 - 12 p(1) = -19 so one of the points would be (1, -19)
what bruh AZ😂 -1 + 8 -12 = -5 (1,-5)

snowflake0531:

@kyledagreat wrote:
it said incorrect for some reason
I'm sorry, I didn't check the other point

KyledaGreat:

oh man , it's alright. i have another one

AZ:

OH MY

AZ:

I CAN'T ADD OR SUBTRACT

AZ:

I DONE GOOFED

AZ:

I HAVE BECOME THE VERY THING I SWORE TO DESTROY

snowflake0531:

😶

KyledaGreat:

Consider the following function. \[a(x) = -x^{2} + 8x - 15\] Find two points on the graph of the parabola other than the vertex and x-intercepts.

KyledaGreat:

it's cool

snowflake0531:

do the same thing; pick a x coordinate and solve for y

KyledaGreat:

okay i'll need you to check it if it's right

KyledaGreat:

let's try 2 a(2) = (2 - 8)^2 - 15

snowflake0531:

are you sure -x^2 + 8x - 15 plugging x as 2 would be \(-(2^2) + 8(2) - 15\)

KyledaGreat:

like that ?

snowflake0531:

well, simplify it now

KyledaGreat:

-3

snowflake0531:

yeah so what's the coordinate point?

KyledaGreat:

2, -3

snowflake0531:

yes, now use another x value

KyledaGreat:

3

KyledaGreat:

\[-(3^2) + 8 (3) - 15 \] correct ?

snowflake0531:

yeah

snowflake0531:

actually you can't use that point because it's a x intercept.. both (3,0) and (5,0) are x intercepts so choose another x value

KyledaGreat:

Ok , 4

KyledaGreat:

how about 4 ?

snowflake0531:

find y

KyledaGreat:

I have -3, 0, and 1

snowflake0531:

?

KyledaGreat:

for y

KyledaGreat:

-3 to use as y ?

snowflake0531:

at x=4... what is the value of y?

KyledaGreat:

1

snowflake0531:

yes, so what's the coordinate point

KyledaGreat:

-8

snowflake0531:

what.... we have the x and y (4,1)

KyledaGreat:

i'm sorry, i had -(1^2) + 8(1) - 15

snowflake0531:

I think you know how to do your questions now

KyledaGreat:

Not really , i just catch on to how you show me the equation to solve it

KyledaGreat:

Was it wrong how i did it ?

snowflake0531:

no, you're right

KyledaGreat:

for my solution , (1, -8) ?

snowflake0531:

yeah

KyledaGreat:

ok, thank you

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