关于对数的计算题 对数计算题
\u6c42\u5173\u4e8e\u6307\u6570\u5bf9\u6570\u7684\u8ba1\u7b97\u98982lg5=lg25=lg(100/4)=lg100-lg4=2lg10-2lg2=2-2lg2=2(1-lg2)\u90a3\u91cc\u6ca1\u770b\u61c2\u518d\u95ee
1/2+1/3+1/6=1\uff0c
\u4e0d\u662f1/36\uff0c
\u6240\u4ee5\u7b54\u6848\u662f1\u4e0d\u662f36
=lg(1/4)/25
=lg1/100
=-2
2log5 10+log5 0.25
=log5 10^2+log5 0.25
=log5 100+log5 0.25
=log5 100*0.25
=log5 25
=2
lg√3
=lg3^(1/2)
=(1/2)*lg3
=0.4771/2
=0.2386
lg3/2=lg3-lg2
=0.4771-0.3010
=0.1761
loga x=1/2loga b-loga c
loga x=loga b^(1/2)-loga c
loga x=loga b^(1/2)/c
x=b^(1/2)/c
绛旓細=(lg5)[lg(5x20)]+2lg2+(lg2)²=(lg5)[lg100]+2lg2+(lg2)²=(lg5)(lg10²)+2lg2+(lg2)²=(lg5)(2lg10)+2lg2+(lg2)²=(lg5)(2)+2lg2+(lg2)²=2(lg5+lg2)+(lg2)²=2lg10+(lg2)²=2+(lg2)²銆愭棰樺彲鑳藉嵃鍒烽敊璇
绛旓細2loga(m-2n)=logam+logan,loga[(m-2n)^2]=loga(m*n),鐢眑og鍑芥暟鐨勫崟璋冩у彲寰楋紝(m-2n)^2=mn m^2-4mn+4n^2=nm m^2-5mn+4n^2=0 (m-n)(m-4n)=0 m=n,m/n=1;鎴栬 m=4n,m/n=4.鑻=n锛屽垯m-2n=-m<0瀵规暟娌℃剰涔夈傛晠m/n=4....
绛旓細搴旇鏄繖鏍 涓嶇啛缁冪殑璇濅竴姝ユ鏉ュ氨濂
绛旓細濡備笅
绛旓細鏂规硶濡備笅锛岃浣滃弬鑰冿細
绛旓細瑙ｏ細2.璁＄畻锛氾紙1锛塴og(3)2/log(27)64=log(3)2/log(3)4 =log(4)2 =1/2.(2) 2^[4+log(2)3=2^[log(2)16+log(2)3]=2^log(2)48 =48.25^[1/2log(5)27+2log(5)2]=5^[log(5)27+4log(5)2]=5^[log(5)27+log(5)16]=5^log(5)432 =432.(3)0.064^(--1...
绛旓細璁＄畻瀵规暟鏈変袱绉嶅父鐢ㄦ柟娉曪紝涓绉嶆槸鍩轰簬甯哥敤瀵规暟锛堜互10涓哄簳锛夛紝鍙︿竴绉嶆槸鍩轰簬鑷劧瀵规暟锛堜互e涓哄簳锛夈1. 璁＄畻甯哥敤瀵规暟锛氬父鐢ㄥ鏁拌〃绀轰负log10(x)锛屽叾涓瓁涓鸿璁＄畻瀵规暟鐨鏁般備娇鐢ㄧ瀛﹁鏁版硶灏唜琛ㄧず涓篴脳10^b鐨勫舰寮忥紝鍏朵腑a涓轰綅浜1鍜10涔嬮棿鐨勬暟锛宐涓烘暣鏁版垨灏忔暟銆傜劧鍚庯紝甯哥敤瀵规暟璁＄畻鍏紡涓猴細log10(x) = b...
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绛旓細lg1/4-lg25 =lg(1/4)/25 =lg1/100 =-2 2log5 10+log5 0.25 =log5 10^2+log5 0.25 =log5 100+log5 0.25 =log5 100*0.25 =log5 25 =2 lg鈭3 =lg3^(1/2)=(1/2)*lg3 =0.4771/2 =0.2386 lg3/2=lg3-lg2 =0.4771-0.3010 =0.1761 loga x=1/2loga b-...
绛旓細锛1锛塴gx=lga-lgb lgx=lg(a/b)x= a/b (2锛塴g(搴曟暟鏍瑰彿3)x=-2/3 lgx /(lg3^1/2)=-2/3 lgx=-2/3lg3^1/2 lgx=lg3^(1/2*-2/3)x=3^(-1/3)锛3锛塴nx=3lnn+lnm lnx=ln(n^3*m ) x=n^3*m 4锛10(鎸囨暟x)=0.1 10(鎸囨暟x)= 10^(-1) x=-1 浜...
