# Cot theta

1. Apr 15, 2010

### mattmannmf

what is Theta?

Cot (2theta) = 2

I have no idea how to get the answer. algebraically or in my calculator

2. Apr 15, 2010

### Char. Limit

Well, you don't have the inverse cottangent button on your calculator, so you might want to turn that cotangent into something that has an inverse button on your calculator... how about tangent?

3. Apr 15, 2010

### mattmannmf

ok:

so cot (2 theta)= 2

can be:
(2 theta) = tan(2)

is that correct?

4. Apr 15, 2010

### Char. Limit

Not quite.

$$cot(\theta)=\frac{1}{tan(\theta)}$$

5. Apr 15, 2010

### mattmannmf

I have no idea than..

6. Apr 15, 2010

### Char. Limit

Try taking the reciprocal of both sides...

I'll do one step for you.

Original equation...

$$cot(2\theta)=2$$

Take the reciprocal...

$$\frac{1}{cot(2\theta)}=\frac{1}{2}$$

And use the identity I told you before...

$$tan(2\theta)=.5$$

And you can solve it from there with a good calculator!

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