Question

實數x滿足log₃x=1+sinθ,則|x－1|+|x－9|的值為

A.8                                                                 B.－8

C.8或－8                                                        D.與θ有關

Answer 1

A

解析:

∵－1≤sinθ≤1,∴0≤1+sinθ≤2，即

0≤log₃x≤2.∴1≤x≤9，|x－1|+|x－9|=x－1+9－x=8.