考點(diǎn):對(duì)數(shù)的運(yùn)算性質(zhì),根式與分?jǐn)?shù)指數(shù)冪的互化及其化簡(jiǎn)運(yùn)算
專題:函數(shù)的性質(zhì)及應(yīng)用
分析:①化帶分?jǐn)?shù)為假分?jǐn)?shù),然后直接利用有理指數(shù)冪的運(yùn)算性質(zhì)化簡(jiǎn)求值;
②直接利用對(duì)數(shù)的運(yùn)算性質(zhì)化簡(jiǎn)求值.
解答:
解:①
-
+
+[(0.064
)
-2.5]
-π
0=
[()2]-[()3]+[()4]+
[(0.064)]-×-1
=
-++(0.064)--1
=
+-1=3;
②lg5
2+
lg8+lg5•lg20+(lg2)
2=2lg5+2lg2+lg5(1+lg2)+(lg2)
2=2(lg2+lg5)+lg5+lg5•lg2+(lg2)
2=2+lg5+lg2(lg5+lg2)
=2+1=3.
點(diǎn)評(píng):本題考查了有理指數(shù)冪的化簡(jiǎn)求值,考查了對(duì)數(shù)的運(yùn)算性質(zhì),是基礎(chǔ)的計(jì)算題.