若是∫（x^2/2-1)dx=x^3/6-x+C.
若是∫（dx/(2x^2-1)
=(1/2)∫dx/(x-√2/2)(x+√2/2)
=(1/2√2)∫[1/(x-√2/2)-1/(x+2/2)]dx=(1/2√2)ln|(x-√2/2)|-(1/4))ln|(x+2/2)|+C=(√2/4)ln|(x-√2/2)/(x+√2/2)|+C.