Answer:
[tex]Cos (\frac{\pi}{3})[/tex]
Step-by-step explanation:
To get the angle in the first quadrant, we need to subtract 2π from the angle given as many times we need UNTIL we get an angle that is between 0 degree and 90 degree (1st quadrant).
Let's start by subtracting 2π from the angle given:
[tex]\frac{7\pi}{3}-2\pi\\=\frac{7\pi -2\pi(3)}{3}\\=\frac{7\pi - 6\pi}{3}\\=\frac{\pi}{3}[/tex]
This angle is in the 1st quadrant, so we don't need to subtract 2π anymore. Thus we can write:
[tex]Cos(\frac{7\pi}{3})=Cos(\frac{\pi}{3})[/tex]
