4.3
original equation
first derivative
Set equal to zero
Solve for x, and then plug numbers from in between
intervals into the
equation.
![]()
-
+ + +
decreasing from
to –6
increasing from –6 to ![]()
from
the intervals of increase and decrease, we
know
the minimum is at –6 because that is where it
goes
from decreasing to increase
second derivative, set equal to zero and solve for x again
and
plug in the numbers from in between the intervals back to ![]()
+ - +
concave up from
to –4, and from 0 to ![]()
concave down from –4 to 0
4.3 Example:
Find the local max and min
values of f using both the first derivative test.
F(x)=
U=x V=x
+4
V’= 2X
Use the quotient rule to find![]()
Put
and solve for the
critical points

- + -
(-2)—(2)
Put your critical points into a number line and see where it
changes from positive to negative or negative to positive.