Question

find a quadratic formula that has x-intercepts of (2,0) and (-6,0) and has a maximum point of (-2,4)

Answer 1

Okay. write down the standard form of a quadratic equation and post it here.

Answer 2

ax^2+bx=c

Answer 3

ax^2+bx+c

Answer 4

No, it should be y = ax^2+bx +c

Answer 5

alright, now substitute (2,0) and (-6,0) in the equation.

Answer 6

maximum point is arrived at when you take the derivative of y with respect to x and equate it to zero.

Answer 7

whats derivative mean

Answer 8

dy/dx

Answer 9

you shouldn't be doing this problem without learning calculus.

Answer 10

my teacher is an idiot and she doesnt teach us

Answer 11

Oh okay. Well, I can only point you to this:
http://www.youtube.com/watch?v=CtRAHmeWSC0

Answer 12

you can also check out khanacademy on youtube. he gives good intro videos on many levels of math

Answer 13

yes. that is right.

Answer 14

You don't need the derivative for this. Just plug in your 3 points into x and y to find 3 linear equations with 3 variables (a, b, and c). Then solve this system of equations to get the coefficients of your quadratic.

Answer 15

It's a system problem, not a calculus one.

Answer 16

lol, yes. polpak is right. sorry.

Answer 17

np. We all have our moments.. For example, I had to be reminded how to integrate odd powers of tan x a few mins ago.

Answer 18

heh. that is true. We all have our moments. :)