Scribe Post April 30, 2010

We started class with a homework quiz. Mr. O'Brien said that homework quizzes are like a doctor's thermometer, and that we shouldn't really stress about them, but they can tell you how much you need to focus on the homework.

We also talked about the final a little bit, which we'll take with the seniors.

And then we took some notes...

Vector Intro
A vector is a directed line segment. There is a vertical and horizontal segment to a vector.

- The length of the vector is the magnitude
- Theta is the direction angle









Homework

29. This problem was trying to find the bearings of ships. We labeled the most of the angles, and used the law of cosines to solve for the triangle. We got C by doing the cos inverse. After finding C we used the law of sines to help solve the rest of the problem.

9. We used the law of cosines, with a^2 being on the left, and then used the law of sines.

21. There was a domain error because it was a bit too short to make a triangle, so the answer is that there is no triangle.

35. Drawing a diagram is really helpful, and then you can use the law of cosines.

The homework for next class is p. 456/3-11 odd, 57-61 odd.