Chapter 10

This past week, we have started off learning the formulas needed in Chapter 10.In order to find the right answers, you MUST know your trig chart since there is no calculators being used. You also have to know your formulas. You need these when finding the exact value, simplifying the expression, etc.

List:

• Cos(A+/-B)=CosACosB-/+SinASinB
• Sin(A+/-B)=SinASinB+/-CosBCosA
• Tan(A+B)=TanA+TanB/1-TaNATanB
• Tan(A-B)=TanA-TanB/1+TanATanB

Double Angles:

• Sin2A=2SinAcosA
• Cos2A=Cos2A-Sin2A
• Cos2A=Cos2A-1
• Cos2a=1-Sin2A
• Tan2A=2TanA/1-Tan2A

Half Angles:

• Sin2a=+/-(Square root)1-cosA/2
• cos2a=+/-(sqaure root)1+cosA/2
• tan2a=1-cosA/sinA=sinA/1+cosA

We use these formulas to find out these unknown trig functions ex:sin75degrees