4楼: Originally posted by
pippi6 at 2014-11-24 12:10:57
左边积分是
2\,K \left( {\it arctanh} \left( {\frac {-2\,Kx+2\,Ka+1}{\sqrt {4\,Ka+ 1}}} \right) -{\it arctanh} \left( {\frac {2\,Ka+1}{\sqrt {4\,Ka+1}}} \right) \right) {\frac {1}{\sqrt {4\,Ka+1}}} ...