00:01
So we have a model for a sub n, the amount of pollutants of sulfur dioxide, i believe it was, and we have 1 .5 plus we have cosine of an n is our variable pi over 26.
00:15
And we need to graph that from zero is less than or equal to n, less than or equal to 104.
00:22
And first of all, we know that the amplitude of that graph is going to end up being a 1, since that there's no coefficient.
00:30
Different and we know that the period of the graph is going to be two pi divided by pi over 26 and remember n is in weeks by the way weeks after january 1st and so this becomes two pi times 26 over pi which gives us 52 so we're talking about this basically being a period of 52 weeks or a year that it's going to finish a cycle.
01:01
Let's see.
01:01
We would have critical points every one -fourth of the period.
01:07
And by critical points, i mean we will have go from a zero to a turning point in a fourth of a period.
01:14
And so if we take 52 and divide it by four, that's going to be 13.
01:19
So every 13 weeks, we're going to end up having a critical point.
01:22
And so let's start to graph this...