[Artik Phrost]

I have a problem:

x/ the square root of (4-x^2)

x is = to 2cos theta. I was wondering if I could simplify the denominator to the square too of 4, which is 2, minus the square root of 2cos^2, which is 2cos.

[Artik Phrost]

If I am able to my final answer would be cos/ 1-cos.


Did anyone else get this answer?

[Capuchin]

You cannot separate square roots under addition like this, for example root(4+9) = root(13) is not the same as root4 + root9 = 5

[Artik Phrost]

So if I were to simplify it I would get 2cos/ 2 times the square root of (2-cos^2). Then I could simplfy that to cos/ the square root of (2-2cos^s)?

[Elisha Grey]

sqrt (4 - x**2) = sqrt (4 - (2 cos theta)**2) = sqrt (4 - 4 cos**2 theta) =
sqrt (4 (1 - cos**2 theta)) = sqrt (2**2 sin**2 theta) = 2sin theta

[Capuchin]

Hi Elisha, this ** stuff is confusing me. The generally accepted notation for raising to a power is ^. Just for your information :)

Or you can use LaTeX, there's a post about it at the top of the maths forum

[cool_dude]

Capuchin I think the reason Elisha uses ** to represent power is because in the programming language Turing to make powers they use **.