> Given a 30-60-right triangle with the short leg equal to x and the
> hypotenuse = 2x ...... the question is find the cosine of angles alpha and
> beta?
>
> I'm using a book that never gives any answers :-( Trigonometry by I.M.
> Gelfand
You say that it's a 30-60-right triangle? Then the angles are
specified as 30, 60, and 90 degrees. So where do alpha and beta
enter the picture?
Anyways, draw a picture, fill in what you know. Invoke
Pythagorus to find the missing data. Then read off your
cosines as the appropriate ratios.
don - 15 Oct 2008 23:26 GMT
> So where do alpha and beta
> enter the picture?
Well, according to the standard alpha represents the first angle in a right
triangle and beta represents the second.
http://en.wikipedia.org/wiki/Greek_letters_used_in_mathematics
Greg Neill - 16 Oct 2008 03:04 GMT
>> So where do alpha and beta
>> enter the picture?
[quoted text clipped - 3 lines]
>
> http://en.wikipedia.org/wiki/Greek_letters_used_in_mathematics
A labelling convention need not always be applied. You simply
have to be specific and consistent in your choices for a
given problem. To avoid confusion, always spell out your
definitions up front for any given problem.
Did you solve your problem?
don - 16 Oct 2008 05:13 GMT
> Did you solve your problem?
Since the Hypotenuse is 2x and the short leg was x, the sine of alpha would
be .5 indicating a 30 degree angle, leaving the other angle to
be 60, so yes I guess I solved the problem if my thinking is correct... this
damn book never gives an answer......
>Given a 30-60-right triangle with the short leg equal to x and the
>hypotenuse = 2x ......
Are you aware that the hypotenuse of a 30-60-90 triangle will *always*
be twice the length of the short leg?

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Michael F. Stemper
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