题目内容
13.计算:(1)${({\frac{1}{2}})^3}×{({\frac{1}{2}})^2}×{({-\frac{1}{2}})^4}×({\frac{1}{2}})$
(2)${[{{{({-\frac{1}{2}})}^n}}]^2}+{({-\frac{1}{2}})^{2n-1}}×\frac{1}{2}$(n是正整数)
分析 (1)根据同底数幂的乘法,即可解答;
(2)根据幂的乘方,即可解答.
解答 解:(1)原式=$(\frac{1}{2})^{3}×(\frac{1}{2})^{2}×(\frac{1}{2})^{4}×\frac{1}{2}$=$(\frac{1}{2})^{3+2+4+1}=(\frac{1}{2})^{10}$.
(2)原式=$(\frac{1}{2})^{2n}-(\frac{1}{2})^{2n-1}×\frac{1}{2}=(\frac{1}{2})^{2n}-(\frac{1}{2})^{2n}$=0.
点评 本题考查了同底数幂的乘法,解决本题的关键是熟记同底数幂的乘法和积的乘方.
练习册系列答案
相关题目
3.已知⊙O1的半径r1=6,⊙O2的半径为r2,圆心距O1O2=3,如果⊙O1与⊙O2有交点,那么r2的取值范围是( )
| A. | r2≥3 | B. | r2≤9 | C. | 3<r2<9 | D. | 3≤r2≤9 |