In Example 4, if 4/7 replaces 3/7, what are the values?

Data from Example 4

If we know that sin θ = 3/7, and that θ is a first-quadrant angle, we know the ratio of the ordinate to the radius vector (y to r) is 3 to 7. Therefore, the point on the terminal side for which y = 3 can be found by use of the Pythagorean theorem:

Therefore, the point (2√10, 3) is on the terminal side, as shown in Fig. 4.16.
Using the values x = 2√10, y = 3, and r = 7, we have the other trigonometric functions of θ. They are

These values are exact. Approximate decimal values found on a calculator are

Transcribed Image Text:

x² + 3² = 72 x = √7²-3² = √499 √40 = 2√10 =