# what is the use of logarithm

2061 Points
8 years ago
For example, the base 10 logarithm of 100 is 2, indicating that 10 raised to the 2nd power is 100.  Given this definition, we can immediately see how logarithms are useful -- if we need to calculate an unknown exponent, the answer will involve a logarithm.
2061 Points
8 years ago
Some common uses of logarithms include

1. Logarithmic scales
Sometimes you only care about how big a number is relative to other numbers.  The Richter, decibel, and pH scales are good examples.  An earthquake with magnitude 8 on the Richter scale is 10 times more powerful than one of magnitude 7.
2. Calculus
The logarithm has some useful properties that make it very common in calculus.  For example, the derivative of the natural logarithm of x is 1/x.
3. Arithmetic
Before calculators became common, many arithmetic problems were solved using logarithms.  For example, we can exploit the fact that log(x*y) = log(x) + log(y) to multiply two large numbers x and y.   Look up the logarithms of x and y in a table, add them, and then use the same table to find the number whose logarithm is closest to the sum.
plz aprve
Nicho priyatham
625 Points
8 years ago
log function has many use
1. to multiply and divide numbers very easily  which u do in physics labs
2. to evaulate limit of 1infinit  type
3. to evulate integrals
4. pscales etc