根号（x减x分之1）的平方加4减根号（x加x分之1）的平方减4√[(x-1/x)²+4]-√[(x+1/x)²-4]=√(x²-2+1/x²+4)-√(x²+2+1/x²-4)=√(x²+2+1/x²)-√(x²-2+1/x²)=√[(x+...