April 8th

At the start of today's class Mr. O'Brien gave us two warm up problems to do, to be solved by hand and then checked using technology. Here's the first problem:

After the warm up problems we went over questions people had from the homework. Number 73 is below:

Next, Mr. OB handed back our first quiz on unit 6! In general, I think most people did fairly well. Remember the two identities on the back are very similar because they use the same identities. If you understand one you should be able to figure out the other. Also, if you still have questions about the information we've covered so far, look over the sections in the textbook or come in to see Mr. OB!

Finally, we took notes on a new set of identities. These are called the sum, difference, double and half angle identities.

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)

You can also find these identities on the front inside cover of your textbook!

Homework p. 404/5, 19, 29, 33, 37, 47, 53, 63, 65, 71

The scribe for next class is Sophie.