√4-(a+1/a)²-√4+(a-1/a)²=√[4-(a^2+2+1/a^2)]-√[4+(a^2-2+1/a^2)]=√[-(a^2-2+1/a^2)]-√[(a^2+2+1/a^2)]=√[-(a-1/a)^2]-√(a+1/a)^2-(a-1/a)^2>=0a-1/a=0a^2-1=0a=±1(a