Question

Find the differential of the function, u=e^(-t)sin(s+2t)

Answer 1

i have du/dt=e^(-t)*d/dt(sin(s+2t) +sin(s+2t)*d/dt(e^-t)
then I got, e^(-t)cos(s+2t)*2+sin(s+2t)*e^(-t)(-1)
then I ggot stuck