Question

dy/dx = sin(x + y) + cos(x+y) differential eqs solve

Answer 1

dydx=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:

dydx=sinxcosy+cosxsiny+cosxcosy+sinxsiny
∴dydx=sinxcosy+sinxsiny+cosxsiny+cosxcosy
∴dydx=sinx(cosy+siny)+cosx(siny+cosy)
∴dydx=sinx(siny+cosy)+cosx(siny+cosy)
∴dydx=(siny+cosy)(sinx+cosx)

Answer 2

i hope this will help u