Question

Look at the unit circle shown below.

Answer 1

Answer:

The correct option is A.

Step-by-step explanation:

Draw a perpendicular form point P on x-axis.

Radius of unit circle is 1 . It means in triangle OPA

Hypotenuse = OP = 1 units

Adjacent= OA = x

Perpendicular = PA = y

In a circle angled triangle,

$\cos \theta = \frac{adjacent}{hypotenuse}$

In triangle OPA,

$\cos \theta = \frac{x}{1}$

$\cos \theta =x$

The x-coordinate of P corresponds to cosθ.

The period of a unit circle is 2π.

Therefore, the correct option is A.

Answer 2

Answer:

A is true.

Step-by-step explanation:

Cos θ = adjacent / hypotenuse = x/1 = x.

Cosθ has a period pf 2π.