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June 30th, 2012, 10:24 AM   #1
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Simplifying trig expression

I have to simplify (or get it in terms of tan I guess?)



I'm not sure how to get the reference angle and subtract the angle 'x' from it to get an expressional value...how would I do this?
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June 30th, 2012, 10:41 AM   #2
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cot(A) = tan(?/2 - A), so cot(2?/3 - x) = tan(x - ?/6).
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June 30th, 2012, 10:55 AM   #3
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Re: Simplifying trig expression

I understand that



Because it's a complementary angle, but I didn't know I could use that identity for this problem and I still don't really know why or how, but nonetheless I tried to create a ratio:

Since








Is this how it's done?

I checked on a calculator and it says it's

I know but

Which is not the answer I got but the solution you provided so I don't know what's going on or where I'm going wrong

I'm trying to visualize it because I think I work better with a visual but I don't know how to imagine this triangle
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June 30th, 2012, 11:00 AM   #4
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Re: Simplifying trig expression

Quote:
Originally Posted by daigo
...
Since





...I don't know what's going on or where I'm going wrong...
You need to write:

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June 30th, 2012, 11:05 AM   #5
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Re: Simplifying trig expression

Oh, is considered the 'x' value of that...I see now. That's kind of confusing; should different variables have been used for the 'x's?
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June 30th, 2012, 11:07 AM   #6
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Re: Simplifying trig expression

Exactly!

That's why [color=#00BF00]skipjack[/color] used A, presumably to avoid that confusion.
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June 30th, 2012, 11:23 AM   #7
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Re: Simplifying trig expression

Ohhh, I thought he just felt like picking 'A' for no reason...I didn't know it was supposed to differentiate the variable 'x' from the one in the other equation
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June 30th, 2012, 11:31 AM   #8
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Re: Simplifying trig expression

The co-function identity:



tells you to take the argument ? on the left side and place it in the right side using the identity.

Hence:

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