# Math Help - Evaluate cot without using a calculator.

1. ## Evaluate cot without using a calculator.

Hello. The questions I have is

Evaluate cot 45° without using a calculator by using ratios in a reference triangle.

I can figure out how to do it with cos, but not cot. I assume I'm missing something really simple on this. If you could please explain to me how I get this answer, I would really appreciate it. Thank you.

2. ## Re: Evaluate cot without using a calculator.

Originally Posted by RiderMind
Hello. The questions I have is
Evaluate cot 45° without using a calculator by using ratios in a reference triangle.
Hint $\sin(45^o)=\cos(45^o)~.$

3. ## Re: Evaluate cot without using a calculator.

Hint: your reference triangle will be a right isosceles triangle.

4. ## Re: Evaluate cot without using a calculator.

I'm sorry guys, I'm still completely lost.

5. ## Re: Evaluate cot without using a calculator.

cot 45° = cotangens 45° = cos(45°)/sin(45°) = ((sqrt(2)/2)/(sqrt(2)/2))=1

6. ## Re: Evaluate cot without using a calculator.

Originally Posted by RiderMind
I'm sorry guys, I'm still completely lost.
You had best learn some very basic trigonometry .

$cot(\theta)=\frac{\cos(\theta)}{\sin(\theta)}~.$