# Homework Help: Simply trigonometry

1. Dec 28, 2011

### luigihs

1. sin θ / √1-sin^2 θ

I dont know this, I know sin = 1 / csc but I not sure how to do this problem :( I dont know about the √1-sin^2 θ

2. Dec 28, 2011

### BloodyFrozen

Try using:

$$sin^{2}\theta+cos^{2}\theta=1$$

3. Dec 28, 2011

### luigihs

I dont understand that sorry can you explain for me? please

4. Dec 28, 2011

### Staff: Mentor

luigihs,
BloodyFrozen has given you a good hint. It is up to you to use the hint. It is against Physics Forums policy to do the work for posters.

5. Dec 28, 2011

### luigihs

But i dont even know how to use that formula how i am suppose to answer that problem ?? what is that ?? for me is just a formula .. but im guessing maybe is not a formula

6. Dec 28, 2011

### micromass

That is the most important formula of entire trigonometry. If you don't know that formula, then I suggest you review your course. There is nothing else we can do for you.

7. Dec 28, 2011

### BloodyFrozen

How are you already simplifying (simple) expressions when you don't know the most basic one? As for my original hint, see if you can get $sin^{2}\theta+cos^{2}\theta=1$ to match a part of the expression that you are trying to simplify.