Mathematics
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KyledaGreat:
Consider the following function.
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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)
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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?
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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
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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
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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.
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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
\(-(2^2) + 8(2) - 15\)
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KyledaGreat:
like that ?
snowflake0531:
well, simplify it now
KyledaGreat:
-3
snowflake0531:
yeah so what's the coordinate point?
KyledaGreat:
2, -3
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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
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KyledaGreat:
Ok , 4
KyledaGreat:
how about 4 ?
snowflake0531:
find y
KyledaGreat:
I have -3, 0, and 1
snowflake0531:
?
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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
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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
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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