Use calculus techniques (can they be a bit more specific? ) to show that the graph of the quadratic function f(x) = ax2 + bx + c, a>0 is decreasing on the interval x<(-b/2a) and increasing on the interval x>(-b/2a).

Use calculus techniques (can they be a bit more specific? ) to show that the graph of the quadratic function f(x) = ax2 + bx + c, a>0 is decreasing on the interval x<(-b/2a) and increasing on the interval x>(-b/2a).

well lets start with what we know and some calculus.

let take the derivative

set the derivative equal to zero.

this is the critical point

now taking the 2nd derivative we get

so the graph is concave up

so the graph is decreasing on

and increasing on

Last edited by TheEmptySet; April 20th 2008 at 05:24 PM.
Reason: typo

Use calculus techniques (can they be a bit more specific? ) to show that the graph of the quadratic function f(x) = ax2 + bx + c, a>0 is decreasing on the interval x<(-b/2a) and increasing on the interval x>(-b/2a).

Uhm...you posted a question like EXACTLY like this like 3 weeks ago...if you need further guidance refer back to that post