Hey Frenchie,

Think of the graph of a trigonomic equation, its a wave that passes the x-axis over and over, and infinite amount of times. Each hit on the x-axis is a solution to the equation, so there is infinitely many solutions. So you may have come up with one solution, but instead the problem tells you that its a different solution. Each solution is only an additon of the period away from the first solution. The "period" of a trigonomic function is the distance between each "hit" on the x-axis (or the distance between the tops or bottoms of each "wave"). Let me show you with a general equation:

Now, the period of the function is given by:

So, say we have the equation:

In the above equation its easy to see, and to check, that:

and

So, looking at this equation, we can find the period to be:

So, looking at the equation again:

We can find the first solution. I assume you know that:

So, we can see that if we let we get:

Which means that that is a "hit" on the x-axis, and that is the "first" solution. But its considered a trivial solution. But, now that you have this solution, you can find any other non-trivial solutions. If we let the first solution (or any solution for that matter) be represented by , then any other solution (for sine and cosine functions) can be found with the following equation (where denotes another solution):

must always be a whole number, in other words:

So, our first solution was

Now, we can figure out the first non-trivial solution with the equation:

Lets let , we know the period is so:

Does that make sense?

Now, see if you can't solve the problems with that information. If not, post back herespecificaly statingwhich problems you'd like some help with, and I'd be glad to assist. I hope this helps