1. Trigonometric Functions of Acute Angles
4.2
Trigonometric Functions of Acute Angles

2. Brainstorm
For 5 minutes, we will take turns coming to the board and writing down anything we remember about right triangle trigonometry. GO!!

3. Know your ratios!

4. Find the six trig ratios for angle A and angle C13 5

5. C B A Special Triangle #1: 45-45-90 Find sin, cos, and
tan of the acute
angles. C B A

6. Special Triangle #2: 30-60-90 Find sin, cos, and tan of the acute
angles.

7. Watch out for calculator errors!
Using the calculator in the wrong angle mode (degrees v radians)
Using the inverse trig keys to evaluate cot, sec, csc (you must type (tan 30)-1 for cot, not tan-1 (30))
Using function shorthand that the calculator doesn’t recognize (you have to type (cos Θ)3 for cos3 Θ)
Not closing parentheses (