00:01
In this question we are required to solve the initial value problem.
00:05
Y -dash plus y is equal to e to the power minus 3 t cosine 2 t by using the laplace transform.
00:17
Here we have y0 is equal to 0.
00:20
So let's see how to solve this question.
00:22
First of all, let's take the laplace transform of each term so we can write laplace transform of y -dash plus laplace transform of y is equal to laplace transform of e to the power minus 3 t cosine 2 t we know that the laplace transform of y -dash is equals to s ys minus y -0 since we have y -0 to 0.
01:00
Therefore laplace transform of y -dash will be equals to s -y -s.
01:08
And we know that the laplace transform of y is equal to y s.
01:19
And it is given that the laplace transform of e to the power a t, cosine b -t is equals to s minus a divided by s minus a to the power t.
01:34
2 plus b square.
01:38
Apply all these formulas.
01:41
So we will have sys plus ys is equals to s minus minus 3 divided by s minus minus minus 3 to the power 2 plus 2 square.
02:06
Now from these two terms let's take out ys as a common so we will have ys into s plus 1 is equals to s plus 3 divided by s plus 3 to the power 2 or we will have s square plus 6 s plus 9 plus 4 so when we further solve this we get ys is equal to s plus 3 divided by s square plus 6 s plus 13 multiplied by s plus 1...