1. Precalculus Day 17

2. Knight’s Charge:
Two ships see a man on top of a 100 ft-cliff at angles of elevation of 30° and 45 °. How far apart are the ships from each other?

3. Law of Cosines
DON’T MEMORIZE THIS AS THREE DIFFERENT FORMULAS…. IT’S THE SAME FORMULA, JUST “ALTERED” BASED ON WHICH SIDE/ANGLE IS UNKNOWN.

4. Example 1:

5. Example 2:
Find the length of side c.

6. Example 3

7. Example 4:
Find the measure of angle A.

8. Choosing Between Law of Sines and Law of Cosines
Now solve triangles 1 and 4!

9. Review Game

10. Victory Lap
Solve the triangle:

11. Homework