Mathematica 教程

# Arithmetic

You can do arithmetic with Mathematica just as you would on an electronic calculator.
This is the sum of two numbers.
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Here the / stands for division, and the ^ stands for power.
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Spaces denote multiplication in Mathematica. The front end automatically replaces spaces between numbers with light gray multiplication signs.
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You can use a * for multiplication if you want to.
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You can type arithmetic expressions with parentheses.
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Spaces are not needed, though they often make your input easier to read.
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 x^y power -x minus x/y divide x y z or x*y*z multiply x+y+z add

Arithmetic operations in Mathematica.

Arithmetic operations in Mathematica are grouped according to the standard mathematical conventions. As usual, 2^3+4, for example, means (2^3)+4, and not 2^(3+4). You can always control grouping by explicitly using parentheses.
This result is given in scientific notation.
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You can enter numbers in scientific notation like this.
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Or like this.
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With Mathematica, you can perform calculations with a particular precision, usually higher than an ordinary calculator. When given precise numbers, Mathematica does not convert them to an approximate representation, but gives a precise result.
This gives the result in terms of rational numbers.
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This gives the approximate numerical result.
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This gives the approximate numerical result with 40 significant digits.
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