# Trouble understanding tangent function

1. Sep 13, 2006

### dianajanielle

I have a physics problem in which I have to use the Tangent function and I really do not know how to use the function. I have never studied Trignometry. I have went to several websites to study tangent functions but it is not coming together for me.

Here the problem that I am working on
A cross country skier skis 1.0 km North and 2.0 km East.
How far and in what direction is she from the starting point?

I have this part correct by using the Pythagorean theorem.

The square root of 1.0 km squared plus 2.0 km squared which equal 2.24km.

What is the magnititude and direction of her displacement resultant.
this is where the tangent function comes into play. I am using the formula: tan 0 = y/x

so I put tan 0= 2.0 / 1.0 = 2 but the correct answer is 63.4 degrees east of north.

I cannot understand how the text book gets 63.4. This is where I am stuck.

2. Sep 13, 2006

### neutrino

I hope you meant tangent of theta($$\theta$$).

You need to find the angle whose tangent is 2.

$$\tan\left(\theta\right) = 2$$
This implies, $$\theta = \arctan(2)$$

arctan is an example of inverse trigonometric functions. Some people also write it as $$\tan^{-1}$$.

3. Sep 13, 2006

### dianajanielle

Now, I am really lost. Does anyone know a site that will explain tangent functions from beginning to end?

4. Sep 13, 2006

### dianajanielle

Oh, I did mean tangent of theta - I just don't know where to find the symbol. Thanks.

5. Sep 13, 2006

### neutrino

6. Sep 13, 2006

### dianajanielle

Yessss!!!! I figured it out! Thank you very much neutrino! I guess I should also say thanks to the scientific calculator that I finally got a hold of.