Question

HELP! Will give MEDAL! What is the equation, in standard form, of a parabola that models the values in the table?
x f(x)
-2 -7
0 3
4 -73


A. y = 4x2 + 3x - 3
B. y = -4x2 - 3x + 3
C. y = -3x2 - 4x + 3
D. y = -3x2 - 3x + 4

Answer 1

ok... there r few steps... first u have to find whether this one is a maximum or a minimum
if its a maximum the leading coefficient of term x^2 would be (-)
if its a minimum the leading coefficient of term x^2 would be (+)

now the graph looks like this if u plot the given values..

so the graph has a maximum shape which means the leading coefficient will be negative

so u can dump the first one...

now
the value of f(3) becomes 3 when x is 0
which means when all the x terms in the quadratic expression becomes 0 there will be a 3 remaining ... which means that the constant is 3 ..

so u can dump the 4th one

now u can take -2 , -7 and plug them to the remaining 2 equations... and u will c
only the third one satisfy the given values...

so the answer will be 3

hope this will help ya!!