Question

In a unit circle, ø = 270º. Identify the terminal point and sin ø.

Answer 1

Terminal point (0, -1); sin θ = -1

Answer 2

Answer:

Terminal point (0, -1); sin Ø = -1 ⇒ A

Step-by-step explanation:

In the unit circle, Ф is the angle between the terminal side and the positive part of the x-xis

• The terminal point on the positive part of the x-axis is (1, 0),which means Ф = 0° or 360° and cosФ = 1, sinФ = 0

• The terminal point on the positive part of the y-axis is (0, 1),which means Ф = 90° and cosФ = 0, sinФ = 1

• The terminal point on the negative part of the x-axis is (-1, 0),which means Ф = 180° and cosФ = -1, sinФ = 0

• The terminal point on the negative part of the y-axis is (0, -1),which means Ф = 270° and cosФ = 0, sinФ = -1

In a unit circle

∵ Ф = 270°

→ By using the 4th rule above

∴ The terminal point is (0, -1)

∴ sinФ = -1

∴ Terminal point (0, -1); sin Ø = -1