1. Unit 5: Introduction to Trigonometry Lesson 5: Evaluate Trig Functions
Accel Precalc
Unit 5: Introduction to Trigonometry
Lesson 5: Evaluate Trig Functions
EQ: How do you evaluate trig functions of angles not found on special triangles?

2. Check MODE of calculator before you evaluate any function.
Using a Graphing Calculator to Approximate the Ratio of All Six Trig Functions:
Check MODE of calculator
before you evaluate any function.
Degrees or Radians

3. Ex. Evaluate each trig function to four decimal places.

4. These are the reciprocals of the ratio not the angle.
What about the reciprocal functions?
Recall:
These are the reciprocals of the ratio not the angle.
NOTE:
DO NOT USE THE SIN-1, COS-1, or TAN-1 KEYS!!

5. Ex. Evaluate each trig function to four decimal places.
You want the reciprocal of the RATIO, not the ANGLE!

6. Using a Graphing Calculator to Approximate an Angle for All Six Trig Functions:
Up to this point, you have been given the angle and have found the ratio.
Now you will be given the ratio and will find the angle.

7. How do you solve algebra equations?
RECALL:
How do you solve algebra equations?
You used inverse operations to solve these equations.
When solving for angles in trig, you need to use inverse trig functions.

8. Recall:
What is function notation?
What is inverse function notation?
Inverse Notation for Trig Functions:

9. sin 60 = _____
Given angle, asks for a RATIO
Given ratio, asks for a ANGLE
Use an inverse trig function to
solve. Respond in degrees.

10. Ex. Evaluate. Round to nearest hundredth of a degree.

11. NOTE: Reciprocal of RATIO, not ANGLE.
Ex. Evaluate. State angle in degrees and minutes.
NOTE: Reciprocal of RATIO, not ANGLE.

12. NOTE: Reciprocal of RATIO, not ANGLE.
Ex. Evaluate. State angle in radians.
NOTE: Reciprocal of RATIO, not ANGLE.

13. In Class Assignment:
Complete Calculator Worksheet Parts I – VI
Textbook p ODDS #39 – 45, 53, 55