Tuesday, January 1, 2013

What is the maximum value of f(x)= -2x^2 -6x + 3 ?

We have the function:


f(x) =
-2x^2 - 6x + 3


We need to find the maximum value of
f(x).


First we look at the coefficient of x^2 which is
negative.


Then the fucntion has a maximum
point.


Now we will find the first derivative and determine
the zeros.


==> f'(x) = -4x - 6 =
0


==> -4x =
6


==> x = -6/4 = -3/2=
-1.5


Now we will find
f(-3/2)


==> f(-3/2) = -2(-3/2)^2 - 6(-3/2) +3 =
-18/4 + 18/2 + 3 = (-18+36 + 12)/4 = 30/4 = 15/2 =
7.5


Then, the
maximum value of the function f(x) is the point


( -1.5,
7.5)

No comments:

Post a Comment

Can (sec x - cosec x) / (tan x - cot x) be simplified further?

Given the expression ( sec x - csec x ) / (tan x - cot x) We need to simplify. We will use trigonometric identities ...