Stupid Math Problem

[Terrik]

So, I'm feeling kind of dumb, but I have an excuse--I haven't done math in 6 years. I'm doing a pre-calc course, and it's relatively easy, but for the life of me, I can't remember how to simply fractions that look like this: ( one half over negative sqrt of 3 over 2 )

1
─
2
----
-√3
─
2




The answer given is
√3
- ─
3
But I have no idea how to get there. I googled a bit, but I couldn't find any examples that had a sqrt as part of a fraction on the denominator.

 

[Dave]

http://www.wolframalpha.com/input/?i=1/2 / -√3[DOUBLEPOST=1409433488,1409433370][/DOUBLEPOST]http://www.wolframalpha.com/input/?i=(1/2) / (-√3/2)

Sorry, I missed the "over two".

 

[Terrik]

http://www.wolframalpha.com/input/?i=1/2 / -√3[DOUBLEPOST=1409433488,1409433370][/DOUBLEPOST]http://www.wolframalpha.com/input/?i=(1/2) / (-√3/2)

Sorry, I missed the "over two".

Heh, it can give me a step by step solution for one easy payment of $65.88 billed annually.

 

[Dave]

Remember, when you divide by a fraction, you invert it and multiply. So it goes from:

(1/2) / (-√3/2) to (1/2) * (2/-√3)

The 2's cancel each other out, leaving you with the -(1/√3)

 

[Terrik]

Remember, when you divide by a fraction, you invert it and multiply. So it goes from:

(1/2) / (-√3/2) to (1/2) * (2/-√3)

The 2's cancel each other out, leaving you with the -(1/√3)

Ahhhhhh there it is. Thanks Dave![DOUBLEPOST=1409433976,1409433715][/DOUBLEPOST]Trig and unit circles may be the death of me, but this just got a lot easier.

 

[Dave]

I may have to bone up on my radians.

 

[Terrik]

I may have to bone up on my radians.

I keep converting my radians into degrees so these dumb unit circles make sense.

 

[Dave]

 

[blotsfan]

You know, I always just took half a circle as pi and a full circle as 2pi but I never know why that was.

 

[Terrik]

You know, I always just took half a circle as pi and a full circle as 2pi but I never know why that was.

Thats because C=2(pi)(r) where r=1 so C=2(pi). I think.

 

[blotsfan]

I meant to say knew. Dave's picture makes a lot of sense. Just something I never really thought about.

 

[PatrThom]

It's the Tau debate again.


--Patrick

 

[fade]

The tau thing is pure pedantry. Leave it to mathematicians. I'm sorry... we physicists can't hear you over the sound of actual work. "What's that?" --engineers. "Sorry, did you say something? I was under my giant pile of money." --the geophysicists.