If sin(theta) = -1/2, and pi < theta < 3pi/2, what is cos(theta)?

Step-by-step explanation:

If is between and

, then we are in third quadrant. This is where x (cosine value) and y (sine value) are both negative.

We are going to use a Pythagorean Identity, namely .

We are going to plug -1/2 for .

That gives us this equation to solve for :

Subtract 1/4 on both sides:

Square root both sides:

We already determine cosine value was negative.

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq

300pi

step-by-step explanation: