济南按摩哪个地方，按高端点还过得去

arctanx =∫1/(1 x 2)dx = x/(1 x 2)2∫(x 2)/(1 x 2)2dx-

arctanx = x/(1 x^2)2(∫(1 x^2)/(1 x^2)^2dx-∫1/(1 x^2)^2dx)

arctanx = x/(1 x^2)2(∫1/(1 x^2)dx-∫1/(1 x^2)^2dx)

arctanx = x/(1 x^2)2 arctanx-2∫1/(1 x^2)^2dx

∫1/(1 x^2)^2dx=(x/(1 x^2)反正切)/2

∫(e^2)(1 x^2)^(-2)dx=(e^2)∫1/(1 x^2)^2dx=(e^2)(x/(1 x^2)arctanx)/2