Question

Find a quadratic model for the set of values:

(-2, 8), (0, 4), (4, 68)

Answer 1

\[y=ax^2+bx+c\] we want \(a, b, c\)
put \(x=0\) get \[4=c\] so we can start with \(c=4\)

Answer 2

now put \(x=-2\) and get
\[8=4a-2b+4\] making
\[4a-2b=-4\]

Answer 3

OK

Answer 4

finally put \(x=4\) and get
\[68=16a+4b+4\]
\[16a+4b=-64\]
\[8a+2b=-32\]

Answer 5

solve
\[2a-b=-2\]
\[4a+b=-16\] and you should be good to go

Answer 6

How is that in y = ?