00:01
Hi, here for the given question we are given differential equation 4y' ' -27y ' -7y is equal to cos h of 7x -1 upon 2 e to the power x.
00:17
Now here first of all we will find the complementary solution.
00:21
So here we will consider the lhs of the equation.
00:24
So here we know that this can be written as 4lambda square -27lambda -7 is equal to 0.
00:32
To simplify this quadratic equation we have lambda -7 let the 4lambda plus 1 equals to 0 which implies lambda is equal to 7 and lambda is equal to lambda2 -1.
00:45
Now here using this values we can say that the complementary solution can be written as y is equal to c e to the power 7x plus this is c1 and this is c2 e to the power minus 1 by 4 x.
01:03
Now here this is the complementary solution.
01:06
Further we need to calculate what is the particular solution.
01:09
So here for the particular solution we will use the variation of parameter matrix.
01:14
So here this is complementary solution.
01:17
For particular solution here we know that the value of y1 is equal to e to the power 7x, y2 is equal to 1 upon e to the power 1 by 4x.
01:33
Similarly y1 ' is equal to derivative will be 7 e to the power 7x and here y2 ' is equal to minus 1 by 4 e to the power 1 upon 4 times of x.
01:48
So here further if we take double derivative so we can observe that a0 of y ' is equal to 4 and here we have fx is equal to cos h of 7x minus 1 by 2 times e to the power x.
02:06
So here further using this value we can say that we have equation as e to the power 7x multiplied with c1 ' of x plus c2 ' of x divided by e to the power x by 4 equals to 0.
02:23
And here further this equation can be rewritten as 7 times e to the power 7x c1 ' of x plus minus c2 ' of x divided by e to the power x by 4.
02:39
Here we have 4 times and here this value is equal to cos of h of 7x minus 1 by 2 times e to the power x divided by.
02:52
So here further we need to find the value of this constant.
02:56
So here in order to calculate this constant we need to calculate the gram scale of the function.
03:00
Here gram scale w is equal to e to the power 7x 1 upon e to the power x by 4.
03:06
Here we have 7 times e to the power 7x and here minus 1 upon 4 times e to the power x by 4.
03:12
So here by calculating the gram scale we have this value equals to 29...