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swiftskier96
Group Title
Help!?!?!?!?
16.
What is the equation, in standard form, of a parabola that models the values in the table?
x  [2, 0, 4]
f(x)  [4, 6, 70]
y = 3x² + 4x – 6
y = 4x² + 3x – 6
y = 6x² + 3x – 4
y = –4x² – 3x + 6
 one year ago
 one year ago
swiftskier96 Group Title
Help!?!?!?!? 16. What is the equation, in standard form, of a parabola that models the values in the table? x  [2, 0, 4] f(x)  [4, 6, 70] y = 3x² + 4x – 6 y = 4x² + 3x – 6 y = 6x² + 3x – 4 y = –4x² – 3x + 6
 one year ago
 one year ago

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ZeHanz Group TitleBest ResponseYou've already chosen the best response.0
Standard form is y=ax²+bx+c. You've got these points on it: (2, 4), (0,6) and (4,70). Just substitute these for x and f(x) in the standard formula. Hint: begin with (0,6) for a quick start!
 one year ago

swiftskier96 Group TitleBest ResponseYou've already chosen the best response.1
So id begin with something like 6 = 3(0)^2 + 4(0)  6 and if i got 6, the equation would be right?
 one year ago

swiftskier96 Group TitleBest ResponseYou've already chosen the best response.1
Whats the answer? @ZeHanz
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
yes, that is the easy way. notice that the last 2 equations will fail
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
because with x=0, just ignore any term with x in it.
 one year ago

swiftskier96 Group TitleBest ResponseYou've already chosen the best response.1
So you're saying it has to be either A or B?
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
y = 3x² + 4x – 6 y = 4x² + 3x – 6 y = 6x² + 3x – 4 y = –4x² – 3x + 6 with x= 0 these turn into y= 6 y= 6 y= 4 y= +6 only the first two have y=6.
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
are you sure you don't have a typo in f(x) values?
 one year ago

swiftskier96 Group TitleBest ResponseYou've already chosen the best response.1
Ok. How do i figure out which ones the right answer? No, those are the right values.
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
test y = 3x² + 4x – 6 replace x with 2 y = 3* 2*2 + 4*2 + 6 what is that?
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
Do I have to multiply and add little numbers for you ?
 one year ago

swiftskier96 Group TitleBest ResponseYou've already chosen the best response.1
I got 38. I think thats wrong... Hold on. Ok seriously? Im trying to do it. Im not as stupid as you think i am. Just give me a second.
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
I think you are smart, but don't like to do this stuff
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
always do it in small methodical steps y = 3* 2*2 + 4*2 + 6 3 * (2*2) is 3*4 = 12 4*2 is 8 6 is 6 add up 1286 = 12 14 = 2
 one year ago

ZeHanz Group TitleBest ResponseYou've already chosen the best response.0
y=ax²+bx+c. Point (0,6), so x = 0, y = 6: \[6=a \cdot 0^2 + b \cdot 0 + c \Leftrightarrow 6 = c\] So now you know c = 6. Now try the next point, (2, 4), so set x = 2 and y = 4 in y=ax²+bx6:\[4=a \cdot (2)^2 + b \cdot 2 6 \Leftrightarrow 4a2b6=4 \Leftrightarrow 4a2b=10\]Last point, (4, 70), so set x = 4 and y = 70:\[70=a \cdot 4^2 + b \cdot 4 6 \Leftrightarrow 16a+4b6=70 \Leftrightarrow 16a+4b=76\]So now you have to solve the system: 4a2b=10 16a+4b=76
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
which does not match 4 . so it looks like equation 2 is the answer we can check: y = 4x² + 3x – 6 replace x with 2: y = 4* 2*2 +3 * 2 6 type this into google 4* 2*2 +3 * 2 6=
 one year ago

swiftskier96 Group TitleBest ResponseYou've already chosen the best response.1
I got 4.
 one year ago

phi Group TitleBest ResponseYou've already chosen the best response.0
so it must be equation 2 if we really wanted to check we could replace x with 4, and we will get 70
 one year ago

ZeHanz Group TitleBest ResponseYou've already chosen the best response.0
So now you have to solve the system: 4a2b=10 multiply with 2 16a+4b=76 leave the same Then it is: 8a4b=20 16a+4b=76  + 24a = 96, so a = 96/24 = 4 Plug a=4 in 4a2b=10, this gives: 162b=10, so 2b=6 and b =3 Formula: y=ax²+bx+c, with a=4, b=3, c=6: Answer: y = 4x²+3x6, that's answer B.
 one year ago
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