If cos ∅ lies in quadrant IV, what can be the value of cos ∅?

Solution;

Given cos ∅ lies in the quadrant IV

∅ is an angle that can be anything between 0° to 360°

360 angle rotation is divided into 4 quarter parts as 0/360, 90°, 180°, 270°

The fourth quadrant means the last quarter (i.e. all angles from 270° to 360°)

The minimum value of cos ∅ = cos 270° = cos(360° - 90°) = cos90° = 0

The maximum value of cos ∅ = cos 360°= cos(360° + 0) = cos0° = 1

Therefore, if ∅ lies in Q-4, cos ∅ can be anything between [0, 1]

If cos ∅ lies in the quadrant IV, what can be the value of cos ∅?

Summary:

If cos ∅ lies in the quadrant IV, anything between [0, 1] can be the value of cos ∅.