# [Tutor] {Possible Spam?} How to use the import math function

Andre Engels andreengels at gmail.com
Wed Jul 20 23:03:47 CEST 2005

```Please, be more precise. When you say "I tried many different
variations", variations of what? And what kind of variations? When you
say "to get it to work", what is "it"? When you say, "nothing
happened", what do you mean exactly - did your program end with no
output? Did it NOT end with no output? Did you get an error message?

Andre Engels

On 7/20/05, Jimmy <ghost04 at mwr.is> wrote:
>
>
>
> My assignment is this:
>
> 4. Read chapter 3 from "How to Think Like a Computer Scientist" (see the
> background materials.) Implement all the examples and exercises in
> Python-Eclipse and after you have successfully run them, export them to be
> combined in a zip with with the other assignments above.
>
>
>
> The course material I have read is this:
> 3.4 Math functions
>
> In mathematics, you have probably seen functions like sin and log, and you
> have learned to evaluate expressions like sin(pi/2) and log(1/x). First, you
> evaluate the expression in parentheses (the argument). For example, pi/2 is
> approximately 1.571, and 1/x is 0.1 (if x happens to be 10.0).
>
> Then, you evaluate the function itself, either by looking it up in a table
> or by performing various computations. The sin of 1.571 is 1, and the log of
> 0.1 is -1 (assuming that logindicates the logarithm base 10).
>
> This process can be applied repeatedly to evaluate more complicated
> expressions like log(1/sin(pi/2)). First, you evaluate the argument of the
> innermost function, then evaluate the function, and so on.
>
> Python has a math module that provides most of the familiar mathematical
> functions. A module is a file that contains a collection of related
> functions grouped together.
>
> Before we can use the functions from a module, we have to import them:
>
> >>> import math
>
> To call one of the functions, we have to specify the name of the module and
> the name of the function, separated by a dot, also known as a period. This
> format is called dot notation.
>
> >>> decibel = math.log10 (17.0)
>  >>> angle = 1.5
>  >>> height = math.sin(angle)
>
> The first statement sets decibel to the logarithm of 17, base 10. There is
> also a function called log that takes logarithm base e.
>
> The third statement finds the sine of the value of the variable angle. sin
> and the other trigonometric functions (cos, tan, etc.) take arguments in
> radians. To convert from degrees to radians, divide by 360 and multiply by
> 2*pi. For example, to find the sine of 45 degrees, first calculate the angle
> in radians and then take the sine:
>
> >>> degrees = 45
>  >>> angle = degrees * 2 * math.pi / 360.0
>  >>> math.sin(angle)
>
> The constant pi is also part of the math module. If you know your geometry,
> you can verify the result by comparing it to the square root of two divided
> by two:
>
> >>> math.sqrt(2) / 2.0
>  0.707106781187
>
> But I have no clue on how to make it work.  I tried many different
> variations to get it to work but in the end nothing happened.  Any help you
> guys can provide would be awesome, I am such a noob to programming it ain't
> even funny.  Thanks……….
>
>
>
>
>
> Jimmy
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>
>
>
```