## Basic math functions: log, log10, roman, trunc

#### Excel Function LN

The LN() function is used to determine the natural logarithm of a number.

The natural logarithm of a number is log value with base-e, the value of e being 2.71.

This function is most often used with Engineering problems.

 Number Formula LN() 1 =LN(L4) 0 4 =LN(L5) 1.38629436111989 45 =LN(L6) 3.80666248977032 0.4 =LN(L7) -0.916290731874155 100 =LN(L8) 4.60517018598809

#### Excel Function LOG

The LOG() function is used to determine the log value of a number to a supplied base value.

This function takes in two parameters; number and base value.

The default base value is 10.

 Number Base Formula LOG() 1 2 =LOG(L16,M16) 0 4 3 =LOG(L17,M17) 1.26185950714291 45 4 =LOG(L18,M18) 2.74592654816484 0.4 10 =LOG(L19,M19) -0.397940008672038 100 1 =LOG(L20,M20) 0

#### Excel Function LOG10

The LOG10() function is used to determine the log value of a number with respect to base 10.

The log value with base 10 is most commonly used in mathematical problems and have extensive applications.

This function takes a single parameter; number.

 Number Formula LOG10() 1 =LOG10(L28) 0 4 =LOG10(L29) 0.602059991327962 45 =LOG10(L30) 1.65321251377534 0.4 =LOG10(L31) -0.397940008672038 100 =LOG10(L32) 2

#### Excel Function ROMAN

The ROMAN() function is used to convert an Arabic numeral to roman form as text.

This function takes two parameters; numeral and form.

The value of form ranges from 0 to 4 which specifies the conciseness of the conversion in increasing order.

This function has a maximum numeral value limited to 3999.

A negative numeral as parameter will result in an error.

 Number Form Formula ROMAN() 1 0 =ROMAN(L41,M41) I 4 1 =ROMAN(L42,M42) IV 45 2 =ROMAN(L43,M43) VL 3999 3 =ROMAN(L44,M44) MMMVMIV 100 4 =ROMAN(L45,M45) C

#### Excel Function TRUNC

The TRUNC() function is used to truncate a number to a specified number of decimal places.

This function takes in two parameters; number and number of digits.

A positive value in number of digits specifies the number of digits to the right of the decimal point.

A negative value in number of digits specifies the number of digits to the left of the decimal point.

If omitted, the number of digits is taken as 0.

 Number No. of digits Formula TRUNC() 23.466 2 =TRUNC(L55,M55) 23.46 4 1 =TRUNC(L56,M56) 4 23.098981 -1 =TRUNC(L57,M57) 20 -887 -1 =TRUNC(L58,M58) -880 0.2344 2 =TRUNC(L59,M59) 0.23