f

2

x
+
x
2
x
coordinate
of
point
P

5
calculate
derivatives
?

4

2
2
4
5
10
15
20
25
The
function
is
concave
up
around
P
=
(

5
,
28
)
.
first
derivative
at
P
is

11
(
slope
of
red
line
)
second
derivative
at
P
is
2