How to integrate 13e^(-0.2x)sin(x)

[killerinstinct]

what is the integral of 13e^(-0.2x) sinx?

i'm using the solving for the unknown integral method.
i did this twice (each time i took the integral twice, moved the unknown integral to the same side, and divided by 13.52?? I still cannot figure out what i am doing wrong.


solve for the diffential. dy/dx = x-4+xy-4y y(0)=4
how can i move it so that x is on one side and y on the other? what is the integral of xy?

 

[hypermorphism]

solve for the diffential. dy/dx = x-4+xy-4y y(0)=4
how can i move it so that x is on one side and y on the other? what is the integral of xy?

The RHS is factorable into a function of x and a function of y.

 

[killerinstinct]

nvm the first problem. I solved it.
the integral =

12.5e^(-.2x) sinx + 2.5e^(-.2x) cosx

 

[killerinstinct]

oops, its should be a - in between.

 

[killerinstinct]

oops still wrong. this is right: -12.5e^(-.2x) cosx - 2.5e^(-.2x) sinx

 

[killerinstinct]

(x-4)(y+1)! Now i see it, thank you!