# Thread: Calculating the value for cotangent.

1. ## Calculating the value for cotangent.

My question says to "calculate the value for cotangent (0) if (0)=270 degrees, given in standard position"

Just calculating it and getting 1.8370 I got it counted wrong, and when I asked on another forum about it they had gone through and what seems like to me, they used quotient identities and put the cos(270)/(sin(270) to equal 0.

Is that the right way to go about this? It didn't say to use quotient identities so I wasn't sure.

There's a second question with the same degree but its asking for the csc (cosecant) of 270, given in standard position.

2. ## Re: Calculating the value for cotangent.

Originally Posted by sterces
My question says to "calculate the value for cotangent (0) if (0)=270 degrees, given in standard position"

Just calculating it and getting 1.8370 I got it counted wrong, and when I asked on another forum about it they had gone through and what seems like to me, they used quotient identities and put the cos(270)/(sin(270) to equal 0.

Is that the right way to go about this? It didn't say to use quotient identities so I wasn't sure.

There's a second question with the same degree but its asking for the csc (cosecant) of 270, given in standard position.
...some smart people you found out there...

It's true.
$\displaystyle \theta=270^{\circ}$
$\displaystyle \cot(\theta)=\frac{\cos(\theta)}{\sin(\theta)}=\fr ac{\cos(270^{\circ})}{\sin(270^{\circ})}=\frac{0}{-1}=0$

EDIT:
$\displaystyle \sec(\theta)=\frac{1}{\cos(\theta)}$

So, what is $\displaystyle \sec(270^{\circ})$ ?

3. ## Re: Calculating the value for cotangent.

Ah, alright, thanks for verifying
sec(270) would be -1 then.

4. ## Re: Calculating the value for cotangent.

Originally Posted by sterces
Ah, alright, thanks for verifying
sec(270) would be -1 then.
Yes!(But only by my definition of sec function)

5. ## Re: Calculating the value for cotangent.

Originally Posted by Also sprach Zarathustra

$\displaystyle \sec(\theta)=\frac{1}{\sin(\theta)}$
$\displaystyle \sec(x) = \dfrac{1}{\cos(x)}$ rather than 1/sin(x).

6. ## Re: Calculating the value for cotangent.

Originally Posted by sterces
Ah, alright, thanks for verifying
sec(270) would be -1 then.

No!

sec(270)=1/cos(270)=1/0

7. ## Re: Calculating the value for cotangent.

Originally Posted by Also sprach Zarathustra
No!

sec(270)=1/cos(270)=1/0
But the question doesn't ask for $\displaystyle \sec(270^\circ)$, it asks for $\displaystyle \csc(270^\circ) = \frac1{\sin(270^\circ)} = \frac1{-1} = -1$.