10-2

So, this week I am going to explain how to work problems using formuals for tan(a + or - B). There are two formulas for these types of problems. They are both exactly the same except for the signs change. So now I am going to give you the formulas.

1. tan(a+B)=tan a + tan B / 1 - (tan a)(tan B)


2. tan(a-B)=tan a - tan B / 1 + (tan a)(tan B)

Now that you have both of the formulas. I am going to work a few examples to help you understand better.

Example 1: tan a=2/3 tan B=1/2

Plug into the formula tan(a+B)

• tan(a+B)= (2/3) + (1/2) / 1 - (2/3)(1/2)


• After you plug into the formula, you just simply solve the problem using basic math.


• Your answer is then going to be 7/4

Example 2: tan a=2 tan B=-1/3

Plug into the formula tan(a-B)

• tan(a-B)=2 - (-1/3) / 1 + (2)(-1/3)


• Once again, all you have to do is solve using basic math.


• Your answer is then going to be 7

I hope you now understand how to work problems using these formula.

--Halie! :D