Question

已知log₂x=3，則x-

1

2

=

2

4

．

Answer 1

分析：把對數(shù)式log₂x=3化為指數(shù)式x=2³=8，因此可得x-

1

2

=

1

8

=

2

4

．

解答：解：∵log₂x=3，∴x=2³=8，∴x-

1

2

=

1

8

=

2

4

．
故答案為

2

4

．

點評：熟練掌握指數(shù)式與對數(shù)式的互化及指數(shù)的運算性質(zhì)是解題的關(guān)鍵．