∫[3^(1/x)/x²]dx=-∫3^tdt……t=1/x=-(3^t)/ln3 +C=-[3^(1/x)]/ln3 +C；∫√x/(√x -1)dx=∫[1+1/(√x-1)]dx=x+∫2√x(d√x)/(√x -1)=x+2x+∫2(d√x)/(√x -1)=3x+ln(√x -1)²+C；∫dx/√(x²-1)=∫...不好意思乱码