设y=arctanex+arctane-x,则dy=_____.
y'=[ex/(1+e2x)]-[e-x/(1+e-2x)]=[ex/(1+e2x)]-[e-xe2x/(1+e-2x)e2x]=[ex/(1+e2x)]-[ex/(1+e2x)]=0,dy=0.
设y=arctanex+arctane-x,则dy=_____.
y'=[ex/(1+e2x)]-[e-x/(1+e-2x)]=[ex/(1+e2x)]-[e-xe2x/(1+e-2x)e2x]=[ex/(1+e2x)]-[ex/(1+e2x)]=0,dy=0.