Question

studying for my final, please check my work!
find the quadratic function that satisfies f(1)=0, f(-1)=14 and f(2)=2
i got 3a-7b+4c

Answer 1

you seem to have calculated the right values for a, b, and c for a quadratic equation of the form: \(ax^2+bx+c=0\)
but have written the answer down incorrectly.

Answer 2

sorry I meant: \(ax^2+bx+c=f(x)\)

Answer 3

how would i right it?

Answer 4

so what you need to do is substitute for a, b and c into this equation.

Answer 5

you found:
a=3
b=-7
c=4

Answer 6

oh so would it be 9a-7b+4c

Answer 7

no - you need to substitute the values for a, b and into this equation:\[f(x)=ax^2+bx+c\]so you should end up with an equation that just has numbers and the variable 'x' within it (\(x^2\) and \(x\) that it).

Answer 8

e.g. you know a=3, so: \(f(x)=3x^2+bx+c\)
now substitute in the values for b and c as well.

Answer 9

oh so just \[3x ^{2}-7x+4\]

Answer 10

thats right - well done! :)

Answer 11

thank you!

Answer 12

yw :)