Given a point on the unit circle corresponding to an angle $\theta$ measured from the positive x-axis, what is the x-coordinate of the point (x, y)?

• A. $1$
• B. $\cos \left(\theta \right)$
• C. $\sin \left(\theta \right)$
• D. $\tan \left(\theta \right)$

Answer: (B)

Verified step by step guidance

1. Recall that a point on the unit circle corresponding to an angle \( \theta \) measured from the positive x-axis has coordinates \( (x, y) \) where \( x = \cos(\theta) \) and \( y = \sin(\theta) \).
2. Understand that the unit circle is a circle with radius 1 centered at the origin \( (0,0) \), so any point on it satisfies the equation \( x^2 + y^2 = 1 \).
3. Since the angle \( \theta \) is measured from the positive x-axis, the x-coordinate of the point is the horizontal distance from the origin to the point on the circle.
4. By definition of cosine in the unit circle context, the x-coordinate is given by \( x = \cos(\theta) \).
5. Therefore, the x-coordinate of the point on the unit circle at angle \( \theta \) is \( \cos(\theta) \).