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Dec 11 2013 11:50pm
I got stumped on this trig proof

[cosx + sinx]/cosx + [cosx-sinx]/cosx = cscxsecx








I converted Csc(x)Sec(x) to 1/sin(x)cos(x) but I just don't know where to begin with the left side.

This post was edited by Jwoww on Dec 12 2013 12:15am
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Dec 11 2013 11:53pm
Find a common denominator on the left side, then you can combine all the terms.
If it's set up like I think it is, things should cancel.
I also recommend using parenthesis or brackets to distinguish between your fractions
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Dec 11 2013 11:54pm
Quote (TritonV8 @ Dec 11 2013 10:53pm)
Find a common denominator on the left side, then you can combine all the terms.
If it's set up like I think it is, things should cancel.
I also recommend using parenthesis or brackets to distinguish between your fractions



Alright I'll give it a shot!
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Dec 12 2013 12:01am
Alright so I multiplied the left side by sinx/sinx to get a common denominator of sinxcosx

The sin^2x cancel each other since (+/-) but

what does sinxcosx + sinxcosx =?

Is that the same as sin^2xcos^2x? If so then it would equal 1 and give me the left being 1/sinxcosx and the right as 1/sinxcosx

but I'm not entirely sure if that step is right.
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Dec 12 2013 12:02am
sinxcosx + sinxcosx = 2sinxcosx

using the trig identity, you can turn that into sin(2x)
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Dec 12 2013 12:04am
also, do you mind writing some parenthesis in? i cant tell what the equation is
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Dec 12 2013 12:05am

Is it [cosx + sinx]/cosx + [cosx-sinx]/cosx
or
cosx + (sinx/cosx) + cosx - (sinx/cosx)

just bold the right one
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Dec 12 2013 12:14am
Quote (TritonV8 @ Dec 11 2013 11:05pm)
Is it [cosx + sinx]/cosx  +  [cosx-sinx]/cosx
or
cosx + (sinx/cosx) + cosx - (sinx/cosx)

just bold the right one


My bad! It's the first one you posted

Been so frustrated with math lately, not very good at it but trying to understand it all.

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Dec 12 2013 12:23am
Quote (Jwoww @ Dec 12 2013 01:14am)
My bad! It's the first one you posted

Been so frustrated with math lately, not very good at it but trying to understand it all.


Hmm, since they have the same denominator, you can just combine the terms on the left side and simplify. You get 2cos(x) / cos(x)
But after doing that, it simplifies to:
2 = csc(x)sec(x)

I may not have the original equation correct.

E: i'm long overdue for some sleep, time for me to hit the sack! But there's plenty of excellent math people here to help. Good luck!

This post was edited by TritonV8 on Dec 12 2013 12:24am
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Dec 12 2013 12:24am
Quote (TritonV8 @ Dec 12 2013 02:23am)
Hmm, since they have the same denominator, you can just combine the terms on the left side and simplify. You get 2cos(x) / cos(x)
But after doing that, it simplifies to:
2 = csc(x)sec(x)

I may not have the original equation correct.


same thing i'm getting...u sure that's the right equation, Jwoww?
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