The logarithm of any number to a given base is the power to which the base must be raised in order to equal the given number. The basic concepts of logarithms are discussed here.
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If ax = N, then, logaN = x
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This is read as log N to the base a. In the equation N and a are positive numbers. Logarithms to the base 10 are known as common logarithms while logarithms to the base e are called natural logarithm. If logarithms are given without mentioning the base it is taken as common logarithm.
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Example: 64 = 43 can be expressed as log464 = 3.
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Logarithms have an Integral and a Decimal part. The integral part is called as characteristic and the decimal part is called as mantissa. The number of digits a number will have will be one more than the characteristic of the logarithmic value of a number.
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Important formulae in logarithms:
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