1-10对数lg：lg1= 0, lg2 = 0.3010, lg3 = 0.4771, lg4 = 0.6021, lg5 = 0.6990, lg...
注意到依AM-GM不等式，有lg2lg5≤((lg2+lg5)/2)∧2=1/4 故只需证ln2＞1/2 又熟知lnx＜x-...
解析 $\left ( {lg5} \right )^{2}+lg2\times lg5+lg2=lg5* ( (lg5+lg2) )+lg2=lg5\times lg\left ( {5\times 2} \right )+lg2=lg5* lg10+lg2=lg5\times 1+lg2=lg5+lg2=lg\left ( {5\times 2} \right )$=lg10=1. 综上所述,答案:1...
lg5×lg20+(lg2)2 Videos Oops. Something went wrong. Please try again. | Khan Academy khanacademy.org Graph quadratics: standard form | Algebra (practice) | Khan Academy khanacademy.org How To Solve Quadratic Equations By Factoring - Quick & Simple! | Algebra Online Course YouTube Compl...
∵ lg10=lg ( (2* 5) )=lg2+lg5 ∴ 1=m+lg5 ∴ lg5=1-m 【答案】 C结果一 题目 已知,,则A.n+mB. n-mC. 2-2n+mD. 2+2n+m 答案 由于又由已知,,则故答案为 C.利用换底公式将lg75用lg2与lg3表示出来,再换成用字母n,m表示即可得. 结果二 题目 若lg5=m,则lg2=A、...
计算:lg ( (lg2+lg5) )=_ _ _ _ _ _ _ _ _ _ .相关知识点: 试题来源: 解析 $\because lg\left ( {lg2+lg5} \right )=lg\left ( {lg\left ( {2\times 5} \right )} \right )=lg ( (lg10) )=lg1=0$ 综上所述填$0$...
$=lg2+lg5=lg10=1$. 综上所述,答案:$1$ (3)由(log)_2 ( (lgx) )=1,可得$lgx=2$, $\therefore x={10}^{2}=100$. 综上所述,答案:$100$ (4)$\left ( {{log}_{3}2+{log}_{9}2} \right )\cdot \left ( {{log}_{4}3+{log}_{8}3} \right )$ $=\left ( {{log}...
1求下列各式的值:(1)log535-log550-log51411)logs 35 10g550logs 14;(2)(lg2)3+(lg5)3+3lg2·lg5;(2)(1g2)3+(lg2),(3)(1-log63)+log62·log618]÷log64.(2)(1g2)3+(lg2), 2求下列各式的值;;;. 3 求下列各式值:1)sin67°30cos67°301)sin67°30;(2)1-2sin275°...
解I：作差比较：\\ \color{red}{\boxed{\begin{eqnarray}\color{blue}{\boxed{\log2\times\log5...