[[Berkas:Logarithm plots.png|right|thumb|upright=1.35|Plot fungsi logaritma, dengan tiga basis yang umum digunakan. Titik-titik khusus {{math|log<sub>''b''</sub> ''b'' {{=}} 1}} ditandai dengan garis bertitik-titik, dan semua irisan kurva pada {{math|1=log<sub>''b''</sub> 1 = 0}}.]]
{{Operasi aritmetika}}
InDalam [[mathematicsmatematika]], the '''logarithmlogaritma''' is theadalah [[inversefungsi functioninvers]] todengan [[exponentiationeksponen]]. ThatItu meansberarti thelogaritma logarithmdari ofsuatu abilangan givenyang number diberikan {{mvar|x}} is theadalah [[exponenteksponen]] todimana whichbilangan anothertetap fixed numberlainnya, the ''[[basebasis (exponentiationeksponen)|basebasis]]'' {{mvar|b}}, mustdinaikkan beuntuk raised,menghasilkan tobilangan producetersebut, that number yaitu {{mvar|x}}. InDalam thekasus simplestyang casesederhana, thelogaritma logarithmmenghitung countsjumlah thekemunculan numberfaktor ofyang occurrencessama ofdalam theperkalian same factor in repeated multiplicationberulang; e.g.misalnya sincekarena {{math|1000 {{=}} 10 × 10 × 10 {{=}} 10<sup>3</sup>}}, the "logarithmbasis base logaritma 10" ofdari 1000 isadalah 3, oratau {{math|log<sub>10</sub> (1000) {{=}} 3}}. The logarithm ofLogaritma {{mvar|x}} toke ''basebasis'' {{mvar|b}} is denoteddinotasikan assebagai {{math|log<sub>''b''</sub> (''x'')}}, oratau withouttanpa parentheses,tanda kurung {{math|log<sub>''b''</sub>  ''x''}}, orbahkan eventanpa withoutbasis the explicit base,eksplisit {{math|log log ''x''}}, whenketika notidak confusionada iskebingungan possible,yang ormungkin when theterjadi, baseatau doesketika notbasis mattertidak suchpenting asseperti indalam [[bignotasi O notationbesar]].
The logarithm base {{math|10}} (that is {{math|1=''b'' = 10}}) is called the decimal or [[common logarithm]] and is commonly used in science and engineering. The [[natural logarithm]] has the [[e (mathematical constant)|number {{mvar|e}}]] (that is {{math|''b'' ≈ 2.718}}) as its base; its use is widespread in mathematics and [[physics]], because of its simpler [[integral]] and [[derivative]]. The [[binary logarithm]] uses base {{math|2}} (that is {{math|1=''b'' = 2}}) and is frequently used in [[computer science]].
