Section 10-2

This week in section 10-2, we learned about the tangent formulas. In this section, the objective was to develop and apply formulas for tan (alpha +/- beta). You still can not use your calculators for anything in this section either. These are the formulas you need to learn and remember:

Tan ( alpha + beta ) = tan alpha + tan beta/1- tan alpha tan beta
Tan ( alpha – beta ) = tan alpha – tan beta/ 1+ tan alpha tan beta
Cot is the opposite (reciprocal) of tan. So, it would be the same formula, just flipped.

Ex: Suppose tan alpha = -1/2 and tan beta = 1/3. Find tan (alpha + beta).
A). Since the problem asks you to find the sum, use the sum formula.
B). Replace the left side with the right and plug in your alpha and beta.
C). -1/2 + 1/3 / 1 – (-1/2)(1/3)
D). -1/7 is your answer.