The differential equation is .
(a)
\Find the solution of the differential equation.
\Apply integral on each side.
\Apply power rule of integral :
.
\ \
.
.
At the initial time and
.
.
Susbtitute in
.
Therefore, the solution of the equation is .
(b) Find the value of when
. \ \
As tends to left side of
then the condition is
.
When there is a small positive number to a negative exponent, then the value is very positive number.
\Hence, the expression approaches to
.
Therefore, .
(c)
\The equation is .
The doomd day will happen at .
The number of rabits breed initially is .
The numbers of rabits breed after three months are .
The prolific breed of rabbits has the growth term is .
The function is , where the growth term is
.
Compare equations and
.
The value of .Susbtitute
,
,
and
in
.
Substitute ,
,
in
.
The doomsday will happen after .
(a) The solution of the equation is .
(b) at
.
(c) The droomday will happen after .