Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
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
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

This Question is Closed

ZeHanzBest 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

swiftskier96Best 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

swiftskier96Best ResponseYou've already chosen the best response.1
Whats the answer? @ZeHanz
 one year ago

phiBest 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

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

swiftskier96Best ResponseYou've already chosen the best response.1
So you're saying it has to be either A or B?
 one year ago

phiBest 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

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

swiftskier96Best 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

phiBest 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

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

swiftskier96Best 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

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

phiBest 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

ZeHanzBest 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

phiBest 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

phiBest 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

ZeHanzBest 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
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.