# tan alpha = 1/2

• Aug 25th 2011, 12:31 PM
Trikotnik
tan alpha = 1/2
I don't know the correct terms in english, but i think it's something like this:

tan alpha = 1/2

I have absolutely no idea how to calculate this. Presumably this follows:

alpha = cot 1/2

But my calculator doesn't have this function, so how do I solve this problem?

Thank you for helping
• Aug 25th 2011, 12:36 PM
anonimnystefy
Re: tan alpha = 1/2
hi Trikotnik

that is not correct.you have to use the arctan(x) function which is the inverse of tan(x),whereas the cot(x) function is 1/tan(x).

Inverse trigonometric functions - Wikipedia, the free encyclopedia
• Aug 25th 2011, 12:49 PM
Siron
Re: tan alpha = 1/2
Don't forget there're infinite solutions therefore:
$\tan(\alpha)=\frac{1}{2} \Leftrightarrow \alpha=\arctan \left(\frac{1}{2}\right)+k\pi$

Like anonimnystefy said if you want to enter cot(...) in your calculator just enter 1/tan(...)
• Aug 25th 2011, 12:51 PM
Trikotnik
Re: tan alpha = 1/2
@anonimnystefy

Yup, I dun goofed. This was my first thought, but the result on my calculator was somehow always wrong. Turns out something that should not have been was turned on. Tried the equation on another calculator and surprise surprise, it's correct.

So:

tan alpha = 1/2
alpha = tan^-1(1/2)

alpha = 26°34 '