Each of these ODEs is linear and homogeneous with constant coefficients, so we only need to find the roots to their respective characteristic equations.
(a) The characteristic equation for
is
which arises from the ansatz 
.
The characteristic roots are 
and 
. Then the general solution is
where 
are arbitrary constants.
(b) The characteristic equation here is
with a root at 
of multiplicity 2. Then the general solution is
(c) The characteristic equation is
with roots at 
, where 
. Then the general solution is
Recall Euler's identity,
Then we can rewrite the solution as
or even more simply as
Answer:
The magnetic field of the earth was discovered by Carl Friedrich Gauss in 1835.
Of course it's possible, because it means that sintheta=-2/5 which satisfies this -1<=sintheta<=1
Is it “b” ? Please tell me please
Africans was exhausted all options in responding to European imperialism. Some groups tried to shut down Europeans by not trading with them and not allowing missionaries to stay with them.
