唔,先把变量凑成1/x,再分部积分,再把1/x视作tanu,就能做出来,至于是不是最好就不造了。
∫[1/x-ln(1/x+√(1/x+√(1+1/x^2)) ]dx=lnx-xln(1/x+√(1/x+√(1+1/x^2)) +∫xdln(1/x+√(1+1/x^2)) =lnx-xln(1/x+√(1+1/x^2)) -ln(x+x^2) +C所以易得原式=2ln(1+√2) -ln2