I don't understand ArcTan. I know it's not just Cotangent, but what is it? How would I solve for, say, ArcTan(Pi/6)? How do I 'set up the triangle' as it were?

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- Sep 15th 2009, 07:49 PMSprintzArcTanx
I don't understand ArcTan. I know it's not just Cotangent, but what is it? How would I solve for, say, ArcTan(Pi/6)? How do I 'set up the triangle' as it were?

- Sep 15th 2009, 07:57 PMseld
arctangent is like arccosine and arcsine.

It's called arc because of the unit circle but there's another name for it I forget what it's like anti ___ I think.

Anyway say I have a number like:

$\displaystyle sin (\frac{\pi}{6})=\frac{1}{2}$ right?

So $\displaystyle arcsin (\frac{1}{2}) = \frac{\pi}{6}$

Arctangent is the same:

say I'm looking at:

$\displaystyle tan(\frac{\pi}{4})=1$

$\displaystyle arctan(1)=\frac{\pi}{4}$

It's just the opposite of what tangent does, you stuff an angle into tangent, and you get a ratio. For arctan/arcsin/arcos you stuff the ratio and it spits out the angle for that ratio.