原式＝1/2〔lg（2x+2*根号下x²-1）-2*lg2+2*lg（根号下x+1减根号下x-1）〕＝1/2〔lg（2x+2*根号下x²-1）-lg4+lg（2x-2*根号下x²-1）〕＝1/2〔lg（2x+2*根号下x²-1）*（2x-2*根...