What is the solution to the Differential Equation #dy/dx = sin(x+y) + cos(x+y)#?
In it's present form this is not separable, but using the sine and cosine sum formula we have:
This is now separable (phew! But you do need to be good with trigonometry!), So "separating the variables" gives us:
The LHS integral is a real pig, This question is more about the separation process than horrific integration, so I will just quote the result which is:
So the solution is: