00:01
Hi, in this question we have to calculate and solve the initial value problem, corresponding to the system of differential equations.
00:12
I -1 over 9 plus 64 i2 -prime -prime equals negative 2, sine t over 24, i3 over 64 plus 9 i3 prime prime minus 64 i -2, i -2 ,000, prime equals 0 and i1 equals i2 plus i3.
00:38
Now this is a mammoth of a problem.
00:41
So i'll give you the gist of how to solve it and you can carry out the calculations completely for yourself.
00:49
Now the first thing we have to do is eliminate i1 from this equation.
00:53
Now you can do that by plugging in this first equation, this third equation into the first equation.
00:59
If we carry that out, then we get that the the first equation can also be written as i2 over 9 plus i3 over 9 plus 64 i2 prime prime equals negative to sine t over 24.
01:17
This is another way of writing the first equation.
01:20
Notice that there is a negative 64 i2 prime prime here and a 64 i2 prime prime here.
01:26
So if we add the second equation to this equation, then we will eliminate the i2 prime prime from this equation.
01:35
If we carry out that, then we'll obtain the equation i2 over 9 plus i3 over 8 plus 9 i3 prime prime is equal to negative 2, sine t over 24.
01:51
Now this doesn't completely give us an equation only in terms of i3, but we're close because we only have i2 over 9.
01:58
Now the only way to remove this i2 factor is by somehow using this i2 prime prime factor to eliminate it from this equation...