(1)∫sin(2x+1)dx=-1/2cos(2x+1)+C(2)∫e^-x/8dx=-8e^-x/8+C(3)∫sinxcosxdx=∫1/2sin2xdx=-1/4cos2x+C(4)=∫1/(ex+e-x)dx=∫e^x/(e^2x+1) dx=∫1/(e^2x+1)de^x=arctan(e^x)+C