00:01
All right, so for this problem, we're going to go ahead and try to find the original differential equation.
00:05
So let's start off by finding the r values.
00:08
And the r values in this case are going to be, well, for the first term right here, we're going to have e to the 0x, which is simply 0.
00:17
And for the second and the third term, we're going to have something of the form a plus b .i simply because it is cosine and sine.
00:26
All right and so our a value in this case is going to be two and it's going to be plus or minus 5 i all right and so we can build this into our original equation and so we'll have terms of r times r minus 2 plus 5i and r minus 2 minus 5i and so let's go ahead and expand these two terms first so we'll have r all times r squared, minus 2r, minus 5 ir, minus 2r, minus 2r, plus 4, plus 10i, let's see, plus 5 ir, minus 10i, and minus 25 i squared.
01:30
And so we can go ahead and cancel out some terms right off the bat.
01:33
So we have these two terms canceling and also these two terms canceling.
01:38
And we can also combine some of these terms...