Logarithm Formulas

There are several logarithm formulas, but some of the most common ones are:

• Logarithmic identity:
  log(b^x) = x * log(b)
• Product rule:
  log(b, xy) = log(b, x) + log(b, y)
• Quotient rule:
  log(b, x/y) = log(b, x) – log(b, y)
• Power rule:
  log(b, x^p) = p * log(b, x)
• Change of base formula:
  log(b, x) = log(a, x) / log(a, b)

Where:

• b is the base of the logarithm
• x and y are the arguments of the logarithm
• p is a constant
• a is a different base, usually chosen to be 10 or e.

Logarithm is an important topic that needs to be prepared well for the Quantitative Aptitude section of exams in India. It requires practicing a lot of questions within time. Logarithmic formulas make it easy to solve questions easily in competitive examinations. The following article covers the concepts, formulas, and rules that a learner needs to know before approaching the questions.

Logarithmic function is inverse to the exponential function. A logarithm to the base b is the power to which b must be raised to produce a given number. For example, is equal to the power to which 2 must be raised in order to produce 8. Clearly, 2^3 = 8 so = 3. In general, for b > 0 and b not equal to 1.