00:01
Hello everyone, the question is given that a function that is force function ft equal to 135 sin 2t and the mass m equal to 15 kg and the spring constant k equal to 135 kg per meter.
00:42
Therefore, equation of motion of spring is m into d2y upon dx2 plus k into y equal to f.
01:09
This implies 15 into y double prime plus 135 into y equal to 375 sin 2t where y of 0 equal to 4 and y prime 0 equal to 2.
01:37
Therefore, we can write that y double prime equal plus 9y equal to 25 sin 2t.
01:50
Therefore, by this equation the auxiliary function is m square plus 9 equal to 0.
02:07
So, m equal to plus minus 3i.
02:11
Therefore, complementary function that is y of c equals to c1 cos 3t plus c2 sin 3t.
02:26
Now to find particular integral that y p equal to 1 upon d square plus 9 into 25 sin 2t.
02:42
This is equals to 25 sin 2t upon this will be minus of 4 plus 9.
02:57
So, 5 so 5 sin 2t.
03:03
This is the y p or particular integral...