Solving a constant coefficient equation – one of the form
– may be accomplished by assuming a solution of the form
The solution will contain two arbitrary constants, which can be found given two boundary conditions on
or some derivative of![]()
Example: Solve the equation
subject to the conditions
when
and
when![]()
Assuming
then
and
Substitute these into the original equation to get
We divide by the none zero factor
to obtain
which factorises to give
We obtain the two solutions![]()
The solution is then
We can find
and
using the conditions given.
(1)
(2)
(1)+(2) gives
then from (1)
so![]()
Example: Solve the equation
subject to the conditions
when
and
when![]()
Assuming
then
and
Substitute these into the original equation to get
We divide by the none zero factor
to obtain
which factorises to give
We obtain the solution
(twice).
The solution is then
We can find
and
using the conditions given.
![]()
so the second condition![]()
![]()
The solution is then![]()
Example: Solve the equation
subject to the conditions
when
and
when![]()
Assuming
then
and
Substitute these into the original equation to get
We divide by the none zero factor
to obtain
which has the solutions
where![]()
The solution is then![]()
![]()
We can find
and
using the conditions given.
![]()
![]()
We don't need to find
and
since
includes the factors
and
values for which are given above.
![]()