1. Trigonometric Functions of Multiples of 30° and 45° & Evaluating Trigonometric Functions with a Calculator

2. Trigonometric Functions of Multiples of 30° & 45°
60°
90°
Sin 1
Cos
Tan
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30°
45° 1 x 1 2
60°
45° 1
45° – 45° – 90° template
30° – 60° – 90° template

3. Trigonometric Functions of Multiples of 30° & 45°
Example 1: Find the exact values of three primary
trigonometric functions of 120°.
Solution: Begin by drawing an angle of 120° in standard
position.
The terminal side of the 120 angle forms an acute 60 angle with the negative x axis.
Now we can use the 30 – 60 – 90 template.
Based on the lengths of the sides of the 30 – 60 – 90 template, we obtain the coordinates of a point P that lies on the terminal side of the 120 angle.
x = -1 because P is in the 2nd quadrant. y 2
30°
120°
60° 1 x

4. Trigonometric Functions of Multiples of 30° & 45°y
30° 2
120°
60° 1 x

5. Homework
Do # 1 – 7 odd numbers only on page 243 from section 7.6 and do # 1 – 15 odd numbers only and # 17 – 21 odd numbers only on page 246 from Section 7.7 for Wednesday June 10th 