## SAT SUBJECT TEST MATH LEVEL 1

## TRIGONOMETRY

**CHAPTER 14**

**Basic Trigonometry**

**WHAT YOU ***DON’T* NEED TO KNOW

*DON’T*NEED TO KNOW

You have just reviewed the ONLY trigonometry you need to know for the Math 1 test. The College Board is very specific about this. Here is a list of several topics in trigonometry that you may have studied in school and that may be tested on the Math Level 2 test but are NOT included on the Math Level 1 test:

• Radian measure (**so keep your calculator in degree mode**)

• Angles whose measures are greater than 90° or less than 0°

• Reference angles

• The reciprocal trigonometric functions: secant, cosecant, and cotangent

• Graphs of the trigonometric functions

• Amplitude and period of the trigonometric functions

• Inverse trigonometric functions

• The law of sines and the law of cosines

• The trigonometric formula for the areas of a triangle and parallelogram

• Double-angle formulas and half-angle formulas

• Trigonometric identities (other than the two previously mentioned)

There is no question on the Math 1 test whose correct solution requires you to use any topic in the preceding list. However, you may always use anything you know.

For example, in the figure below, the area of *ABC* is (*AC* )(4).

So in order to calculate the area, you need to know the value of *AC*. Since *ABC* is a 30-60-90 right triangle, by KEY FACT H8, .

You can also find *AC* by using the tangent ratio: tan 30° = and solving for *AC.* If you know the law of sines and for any reason you prefer to use it, of course you may: