对数函数运算题 对数函数的运算公式.
\u5bf9\u6570\u51fd\u6570\u8fd0\u7b97\u98981\u3001a^log(a)(b)=b 2\u3001log(a)(a)=1 3\u3001log(a)(MN)=log(a)(M)+log(a)(N); 4\u3001log(a)(M\u00f7N)=log(a)(M)-log(a)(N); \u3000 5\u3001log(a)(M^n)=nlog(a)(M) 6\u3001log(a)[M^\uff081/n\uff09]=log(a)(M)/n \u6269\u5c55\u8d44\u6599\uff1a\u4e00\u822c\u5730\uff0c\u5bf9\u6570\u51fd\u6570\u4ee5\u5e42\uff08\u771f\u6570\uff09\u4e3a\u81ea\u53d8\u91cf\uff0c\u6307\u6570\u4e3a\u56e0\u53d8\u91cf\uff0c\u5e95\u6570\u4e3a\u5e38\u91cf\u7684\u51fd\u6570\u3002\u5bf9\u6570\u51fd\u6570\u662f6\u7c7b\u57fa\u672c\u521d\u7b49\u51fd\u6570\u4e4b\u4e00\u3002\u5176\u4e2d\u5bf9\u6570\u7684\u5b9a\u4e49\uff1a\u5982\u679cax=N\uff08a>0\uff0c\u4e14a\u22601\uff09\uff0c\u90a3\u4e48\u6570x\u53eb\u505a\u4ee5a\u4e3a\u5e95N\u7684\u5bf9\u6570\uff0c\u8bb0\u4f5cx=logaN\uff0c\u8bfb\u4f5c\u4ee5a\u4e3a\u5e95N\u7684\u5bf9\u6570\uff0c\u5176\u4e2da\u53eb\u505a\u5bf9\u6570\u7684\u5e95\u6570\uff0cN\u53eb\u505a\u771f\u6570\u3002\u4e00\u822c\u5730\uff0c\u51fd\u6570y=logax\uff08a>0\uff0c\u4e14a\u22601\uff09\u53eb\u505a\u5bf9\u6570\u51fd\u6570\uff0c\u4e5f\u5c31\u662f\u8bf4\u4ee5\u5e42\uff08\u771f\u6570\uff09\u4e3a\u81ea\u53d8\u91cf\uff0c\u6307\u6570\u4e3a\u56e0\u53d8\u91cf\uff0c\u5e95\u6570\u4e3a\u5e38\u91cf\u7684\u51fd\u6570\uff0c\u53eb\u5bf9\u6570\u51fd\u6570\u3002\u5176\u4e2dx\u662f\u81ea\u53d8\u91cf\uff0c\u51fd\u6570\u7684\u5b9a\u4e49\u57df\u662f\uff080\uff0c+\u221e\uff09\uff0c\u5373x>0\u3002\u5b83\u5b9e\u9645\u4e0a\u5c31\u662f\u6307\u6570\u51fd\u6570\u7684\u53cd\u51fd\u6570\uff0c\u53ef\u8868\u793a\u4e3ax=ay\u3002\u56e0\u6b64\u6307\u6570\u51fd\u6570\u91cc\u5bf9\u4e8ea\u7684\u89c4\u5b9a\uff0c\u540c\u6837\u9002\u7528\u4e8e\u5bf9\u6570\u51fd\u6570\u3002\u6709\u7406\u548c\u65e0\u7406\u6307\u6570\u5982\u679c \u662f\u6b63\u6574\u6570, \u8868\u793a\u7b49\u4e8e \u7684 \u4e2a\u56e0\u5b50\u7684\u52a0\u51cf: \u4f46\u662f\uff0c\u5982\u679c\u662f \u4e0d\u7b49\u4e8e1\u7684\u6b63\u5b9e\u6570\uff0c\u8fd9\u4e2a\u5b9a\u4e49\u53ef\u4ee5\u6269\u5c55\u5230\u5728\u4e00\u4e2a\u57df\u4e2d\u7684\u4efb\u4f55\u5b9e\u6570 \uff08\u53c2\u89c1\u5e42\uff09\u3002\u7c7b\u4f3c\u7684\uff0c\u5bf9\u6570\u51fd\u6570\u53ef\u4ee5\u5b9a\u4e49\u4e8e\u4efb\u4f55\u6b63\u5b9e\u6570\u3002\u5bf9\u4e8e\u4e0d\u7b49\u4e8e1\u7684\u6bcf\u4e2a\u6b63\u5e95\u6570 \uff0c\u6709\u4e00\u4e2a\u5bf9\u6570\u51fd\u6570\u548c\u4e00\u4e2a\u6307\u6570\u51fd\u6570\uff0c\u5b83\u4eec\u4e92\u4e3a\u53cd\u51fd\u6570\u3002\u5bf9\u6570\u53ef\u4ee5\u7b80\u5316\u4e58\u6cd5\u8fd0\u7b97\u4e3a\u52a0\u6cd5\uff0c\u9664\u6cd5\u4e3a\u51cf\u6cd5\uff0c\u5e42\u8fd0\u7b97\u4e3a\u4e58\u6cd5\uff0c\u6839\u8fd0\u7b97\u4e3a\u9664\u6cd5\u3002\u6240\u4ee5\uff0c\u5728\u53d1\u660e\u7535\u5b50\u8ba1\u7b97\u673a\u4e4b\u524d\uff0c\u5bf9\u6570\u5bf9\u8fdb\u884c\u5197\u957f\u7684\u6570\u503c\u8fd0\u7b97\u662f\u5f88\u6709\u7528\u7684\uff0c\u5b83\u4eec\u5e7f\u6cdb\u7684\u7528\u4e8e\u5929\u6587\u3001\u5de5\u7a0b\u3001\u822a\u6d77\u548c\u6d4b\u7ed8\u7b49\u9886\u57df\u4e2d\u3002\u5b83\u4eec\u6709\u91cd\u8981\u7684\u6570\u5b66\u6027\u8d28\u800c\u5728\u4eca\u5929\u4ecd\u5728\u5e7f\u6cdb\u4f7f\u7528\u4e2d\u3002\u590d\u5bf9\u6570\u590d\u5bf9\u6570\u8ba1\u7b97\u516c\u5f0f\u590d\u6570\u7684\u81ea\u7136\u5bf9\u6570\uff0c\u5b9e\u90e8\u7b49\u4e8e\u590d\u6570\u7684\u6a21\u7684\u81ea\u7136\u5bf9\u6570\uff0c\u865a\u90e8\u7b49\u4e8e\u590d\u6570\u7684\u8f90\u89d2\u3002
1\u3001a^log(a)(b)=b \u3000\u3000
2\u3001log(a)(a)=1 \u3000\u3000
3\u3001log(a)(MN)=log(a)(M)+log(a)(N); \u3000\u3000
4\u3001log(a)(M\u00f7N)=log(a)(M)-log(a)(N); \u3000
5\u3001log(a)(M^n)=nlog(a)(M) \u3000\u3000
6\u3001log(a)[M^\uff081/n\uff09]=log(a)(M)/n
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\u6709\u7406\u548c\u65e0\u7406\u6307\u6570
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绛旓細1锛宭og锛圡N锛=logM+logN锛2锛 log锛圡/N锛=logM-logN锛3锛宭ogM锛緉=nlogM锛孖=-blogab =-0.3log2(0.3)=-log2(0.3^0.3)
绛旓細1.鍑芥暟y=f(x)鏄畾涔夊煙涓篬-6锛6]鐨勫鍑芥暟銆傚張鐭=f(x)鍦╗0锛3]涓婃槸涓娆″嚱鏁帮紝鍦╗3锛6]涓婃槸浜屾鍑芥暟锛屼笖褰搙灞炰簬[3锛6]鏃讹紝f(x)灏忎簬绛変簬f(5)=3,f(6)=2,璇曟眰y=f(x)鐨勮В鏋愬紡銆傜瓟:鍑芥暟y=f(x)鏄畾涔夊煙涓篬-6锛6]鐨勫鍑芥暟銆傚張鐭=f(x)鍦╗0锛3]涓婃槸涓娆″嚱鏁帮紝鍦╗3锛6...
绛旓細銆1/2锛3锛夋垨鑰咃紙1/2锛3锛夋棰樼殑鐭ヨ瘑鐐逛富瑕佹湁锛1锛屽鍚鍑芥暟鐨勫鍑忔у垽鏂傦紙澶栧嚱鏁版槸鍗曡皟閫掑鐨勬椂鍊欙紝鍚屽鍒欏锛屽惁鍒欏垯鍑忥級2锛屽唴鍑芥暟鍗充簩娆″嚱鏁扮殑椤剁偣鍒ゆ柇锛堟垜鏄洿鎺ョ敤姹傚涔嬪悗锛屼护瀵煎嚱鏁=0寰楀埌鐨勶級锛屼富瑕佸氨鏄繖涓や釜鍏抽敭鐨勫湴鏂癸紝3锛岃繕鏈夌殑璇濓紝灏辨槸浜屾鍑芥暟涓鑸彲浠ュ寲绠涓轰袱涓椤瑰紡鐩镐箻鐨勫舰寮...
绛旓細涓庢寚鏁板嚱鏁般瀵规暟鍑芥暟鐩稿叧鐨勫簲鐢ㄩ杈冨锛屽浜哄彛鐨勫闀裤佺幆淇濈瓑绀句細鐑偣闂锛屽浗姘戠敓浜ф诲肩殑澧為暱銆佹垚鏈殑澧為暱鎴栭檷浣庛佸钩鍧囧闀跨巼绛夌粡娴庣敓娲婚棶棰橈紝鏀惧皠鎬х墿璐ㄧ殑铚曞彉銆佹俯搴︾瓑鐗╃悊瀛︾闂绛夈傛寚鏁板嚱鏁皔=ax锛坅锛0锛屼笖a鈮1锛夛紝瀵规暟鍑芥暟y锛漧ogax锛坅锛0锛屼笖a鈮1锛夛紝鎸囨暟鍑芥暟y=ax涓庡鏁板嚱鏁皔=logax浜掍负鍙...
绛旓細鍑芥暟y=log(a)X(鍏朵腑a鏄父鏁,a>0涓攁涓嶇瓑浜1锛夊彨鍋瀵规暟鍑芥暟 锛屽畠瀹為檯涓婂氨鏄寚鏁板嚱鏁扮殑鍙嶅嚱鏁帮紝鍙〃绀轰负x=a^y锛屽洜姝ゆ寚鏁板嚱鏁伴噷瀵逛簬a鐨勮瀹氾紝鍚屾牱閫傜敤浜庡鏁板嚱鏁般傚鏁扮殑杩愮畻鎬ц川锛氬綋a>0涓攁鈮1鏃,M>0,N>0,閭d箞锛氾紙1锛塴og(a)(MN)=log(a)(M)+log(a)(N);锛2锛塴og(a)(M/N)=log(a...
绛旓細鎴戜篃鏉ュ紶鍥 鍛靛懙~~鍐欑殑涓嶅ソ鐪 澶氬鍖呮兜~
绛旓細log鐨璁$畻灏辨槸涔樻柟鐨勯嗚繃绋嬨傚鏋渁鐨剎娆℃柟绛変簬N锛坅>0锛屼笖a涓嶇瓑浜1锛夛紝閭d箞鏁皒鍙仛浠涓哄簳N鐨瀵规暟锛坙ogarithm锛夛紝璁颁綔x=logaN銆傚叾涓紝a鍙仛瀵规暟鐨勫簳鏁帮紝N鍙仛鐪熸暟銆傝绠楁柟寮忥細鏍规嵁2^3=8锛屽彲寰條og2 8=3銆
绛旓細瀵规暟鍑芥暟涓殑 "ln" 鏄嚜鐒跺鏁帮紝浠ュ簳鏁颁负甯告暟 ee 鐨勫鏁般璁$畻鑷劧瀵规暟鐨勪竴鑸楠ゅ涓嬶細鎵撳紑璁$畻鍣細 濡傛灉浣犱娇鐢ㄨ绠楀櫒锛岄氬父璁$畻鍣ㄤ笂浼氭湁涓涓互 "ln" 琛ㄧず鐨勬寜閽傝緭鍏ユ暟鍊硷細 杈撳叆鑷劧瀵规暟鐨勫弬鏁帮紝涔熷氨鏄 lnln 鍚庨潰鐨勫笺備緥濡傦紝濡傛灉瑕佽绠 ln(2)ln(2)锛屽氨杈撳叆 2銆傛寜涓 "ln" 鎸夐挳锛 鍦ㄨ緭鍏...
绛旓細lg5=lg(10/2)=lg10-lg2=1-lg2 lg2^(鈭3)=鈭3*lg2 1/2*lg0.36=lg(0.36^0.5)=lg0.6=lg(6/10)=lg6-lg10=lg6-1 lg5*lg8000+[lg2^(鈭3)]^2 / lg600-1/2*lg0.36 =(1-lg2)*lg(2^3*10^3)+(鈭3*lg2)^2 / lg(6*10^2)-lg0.6 =(1-lg2)*(3...
绛旓細1