积分 dx/[e^x+e^(2-x)]请看清楚题目作答

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积分 dx/[e^x+e^(2-x)]请看清楚题目作答

积分 dx/[e^x+e^(2-x)]请看清楚题目作答
积分 dx/[e^x+e^(2-x)]
请看清楚题目作答

积分 dx/[e^x+e^(2-x)]请看清楚题目作答
令t=e^x,则dt=e^x*dx=tdx
dx/[e^x+e^(2-x)]=dx/[t+(e^2/t)]=tdx/(t^2+e^2)
=dt/(t^2+e^2)
令t/e=u,t=eu,则dt=edu,
dt/(t^2+e^2)=edu/[e^2(1+u^2)]=du/e(1+u^2)
∫dx/[e^x+e^(2-x)]
=∫du/e(1+u^2)=(1/e)∫du/(1+u^2)
=arctan(u)/e+C1
=arctan(t/e)/e+C2
=arctan(e^x/e)/e+C3=arctan[e^(x-1)]/e+C

∫[e^x+e^(2-x)]dx
=∫e^xdx+∫e^(2-x)dx
=e^x+C1-∫e^(2-x)d(2-x)
=e^x+C1-e^(2-x)+C2
=e^x-e^(2-x)+c

dx/[e^x+e^(2-x)]
=e^x-e^(2-x)