Question

已知a小于0化简√4-（a+1/a)-√4+(a-1/a)

Answer 1

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