Calculation of logarithms in the training process often comes to an end with record of a simple form of logarithmic expression. However in practice sometimes it is necessary to calculate exact value of a logarithm of number on the set basis. And logarithm accuracy sometimes is required quite high. The majority of the calculated logarithms are irrational numbers. Earlier numerical value of a logarithm was determined by special logarithmic tables. Today it is possible to find a number logarithm by means of the calculator, having carried out a number of simple actions.
It is required to you
- Engineering calculator
Instruction
1. At the calculator, as a rule, there is a function of calculation of a natural logarithm, that is logarithm of any number on the basis e. But proceeding from properties of a logarithm and rules of carrying out operations over them, it is possible to calculate a logarithm on the calculator on any other basis. For this purpose it is necessary to apply a transition formula from the basis e to the new basis necessary to you.
2. Taking into account a transition formula, execute calculation of a logarithm of number b on the basis and on the calculator, remembering the received intermediate results in memory of the device. For this purpose at first calculate a natural logarithm of number and which is the basis of your initial logarithm. Press on the calculator a key [MC] for zeroing of memory of the calculator. Then gather number of the basis and and press function of a natural logarithm [ln].
3. Keep the received value of a logarithm in memory by means of the button [M+]. Further clean a window of results for further calculations with a key of [C].
4. Calculate a natural logarithm of number b set in your initial logarithm. For this purpose gain the sequence on the calculator: at first number b, then [ln]. Receive a logarithm of the set number, but on the basis e.
5. Calculate a logarithm on the set basis and. For this purpose it is necessary to divide, received by the last, value of a logarithm of b into the intermediate value of a logarithm which is available in memory and. Press consistently the buttons: [/] and [MR]. On the screen to be highlighted the first calculated number. Make division, having pressed a key [=]. The calculator will give you on the screen value which is a logarithm of the set number a on b basis.