The graphs of the inequalities are ,
,
and
.
Graph the inequalities ,
,
and
.
Observe the graph:
\ on
.
\
Moments and center of mass of a planar lamina:
\Let and
be continuous functions such that f
on
, and consider the planar lamina of uniform density
bounded by the graphs of
and
.
The moments about the -and
-axis are
.
.
The center of mass is
and
, where
is the mass of the lamina.
Find the area of the region .
.
Substitute .
Apply derivative on each side with respect to .
.
Substitute and
.
Substitute and
.
.
The area of the region is .
Find .
.
.
Find .
Since the graph is symmetrical about the -axis, center of mass lies on the axis of symmetry
.
The center of mass is
and
.
Substitute and
in
.
.
Substitute and
in
.
.
The centroid of the region is .
The centroid of the region is .