Question

Draw the angle 0=-pi/2 in standard position find the sin and cos

Answer 1

An angle in standard position has the vertex at the origin and the initial side is on the positive x-axis.

Thus, the initial side of the angle is:

Now, half the circumference measures pi, thus, pi/2 is a quarte of the circumference. As we want to find the angle -pi/2, then we need to rotate the terminal side clockwise:

Find the sine and the cosine.

The sine and the cosine in the unit circle are given by the coordinates as follows:

`(\cos\theta,\sin\theta)`

As can be seen in the given unit circle, the terminal side is located at:

`(0,-1)`

Thus, the values of cosine and sine are:

`\begin{gathered} \cos\theta=0 \\ \sin\theta=-1 \end{gathered}`