Question

find a quadratic function in standard for that has the following points: (1,-2); (2,-2); (3,-4).

Answer 1

plug each point into equation:
\[y = ax^{2} +bx +c\]
this will give 3 equations with 3 variables (a,b,c)
solve system of 3 equations with matrices or elimination

Answer 2

how do i place them in that equation without an a b and c ?

Answer 3

for (1,-2) ..... x=1 and y=-2

==> -2 = a*(1)^2 + b*1 + c
--> -2 = a+b+c

Answer 4

if i plug it in wouldnt a still be squared or somethin ?

Answer 5

a is not squared ... the "x" is squared

Answer 6

oh. okay
so after i do that do i add all of them together ?

Answer 7

well you need to know how to solve a system of 3 equations

Answer 8

what do you mean ?

Answer 9

after plugging in the points, you get

a + b +c = -2
4a +2b +c = -2
9a + 3b +c = -4

you need to solve for a,b,c

Answer 10

im trying to write down and figure which numbers can work for all three

Answer 11

a=-1
b=3
c=-4

Answer 12

y=-1x^2 + 3x -4

Answer 13

omg thank you. i was going to be thinking forever. and im extra tired. i know i shoulda did it by myself but idk. may you help me with one more question:
The weight of a tennis ball must be 57.7 grams, plus or minus 1.7 grams. write an absolute value inequality to illustrate this rule...

Answer 14

"Oh my god, thank you. I would have been thinking about this for a long time, and I'm extra tired today. I know that I should have solved it on my own. Can you help me with another problem..."

|57.7-x|<1.7

Answer 15

thank you