∫ 1/(2x²-1) dx
=∫ 1/[(√2x-1)(√2x+1)] dx
=(1/2)[∫ 1/(√2x-1) -∫ 1/(√2x+1) ]dx
=(√2/4)[∫ 1/(√2x-1) -∫ 1/(√2x+1) ]d(√2x)
=(√2/4)(ln|√2x-1|-ln|√2x+1|)
=(√2/4)ln(|√2x-1|/|√2x+1|)