Solve:
du/dt = (sin t) / (u^2 + 1)
So far I got:
arctan u = -ln |csc t + cot t| + C
I'm not sure where to go from there. Thank you so much for the help!
Separate the variables:
(u^2 + 1) du = sin t dt
Now integrate
2/3 u^3 + u = -cos t