April 9th Class

Today we started off class with the warm up. It said, Solve on [0,2) a) b) . We found that there were several answers for A, which were . So the short answer is . A common mistake on A is not including the plus or minus when the right side is squared. For b, the four answers are

Then we went over the homework. The first problem we went over was #33. On this problem we used the Squaring both sides method from page 393. This method squares both sides which allow you convert it to a quadratic type, which is easier to solve. Other problems we went over were numbers 55, 73, and 75.

Then we looked at a new set of identities. These are called the sum, difference, double and half angle identities. THESE IDENTITIES DO NOT NEED TO BE MEMORIZED. We will have access to them during quizzes and tests.
The six identities are:
Cos(a-b)=Cos(a)Cos(b)+Sin(a)Sin(b)
Cos(a+b)=Cos(a)Cos(b)-Sin(a)Sin(b)
Sin(a-b)=Sin(a)Cos(b)-Cos(a)Sin(b)
Sin(a+b)=Sin(a)Cos(b)+Cos(a)Sin(b)
Tan(a-b)=
Tan(a+b)=
These identities are also located on the front cover of your book

Towards the end we went over and corrected the quiz.

Homework p. 404/5, 19, 29, 33, 37, 47, 53, 63, 65, 71 [these questions should be answered without the use of technology, but be sure to use our new identities!]

Everyone has scribed 3 times now so someone will have to step up next class

Keegan