Question

If 0° ≤ Θ≤ 360°, then find angle(s) Θ.

cosΘ= -1/2

Answer 1

There are two possible solutions for angle Θ, as cosine is negative in the second and third quadrants.

Using the inverse cosine function on a calculator, we can find the two possible solutions for Θ:

Θ = 120° (in the second quadrant)

Θ = 240° (in the third quadrant)

Therefore, the possible angles for Θ are 120° and 240°.