Help 41,42 ​

41. cos 300=1/2

41. Here is the solution:

Imagine the unit circle: 

We know that 300 degrees is in the fourth quadrant, where cosine is positive.

300 degrees has a reference angle of 60 degrees, since it is 60 degrees away from the x-axis

Since \(\cos{60º}=\frac12, \cos{300º}=\frac12\)

I hope this helped,

Gavin

42. Assuming s is the major arc, here is the solution:

π here is 180 degrees, so 5π/3 is also 5 * 180 / 3 = 300

That angle is 300 degrees. 

The circumference is 2r * π, where r is the radius and π is 3.1415...

The circumference is 18π. 

Since the major arc is 300/360 or 5/6 of the circumference, it is 

5/6 * 18π = 15π long. 

This in decimal is 15 • 3.141...=47.124...

A. 

I hope this helped,

Gavin

Thanks!