# Cos^2+Sin^2 = 1 even with coefficients?

1. Feb 20, 2015

### Tyrion101

I have a problem that works out to this s, but with a coefficient, what do I do with it from this point?

2. Feb 20, 2015

### SteamKing

Staff Emeritus
If you have a problem, please post it in one of the HW forums and use the HW template. As it stands, it is unclear what you are trying to find.

3. Feb 20, 2015

### Tyrion101

The basic trig identity I was merely asking if it applied also when there were coefficients, can you factor them out if you realize it is the most basic of identities?

4. Feb 20, 2015

### SteamKing

Staff Emeritus
If you are asking does x * cos2θ + x * sin2θ = x, then the answer is yes.

If you are asking does y * cos2θ + x * sin2θ = y + x, then the answer is no.

Remember, the normal rules of algebra in making the proper simplification.

5. Feb 20, 2015

### Mentallic

Please give an example, because you're misusing the term "coefficient".

6. Feb 20, 2015

### Tyrion101

An example: 5Cos^2x +5Sin^2x, I'm on my iPad and don't have access to theta, so just assume it's there. Are these treated as separate variables or the same since if you took away the 5 it would equal 1?

7. Feb 20, 2015

### Mentallic

That's equivalent to one of the results Steamking posted.

Try factoring out the number 5, and then apply the rule that you know.

8. Feb 20, 2015

### Tyrion101

Ok thanks! I just wasn't sure how that rule worked with this kind of problem.