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# Help 41,42 ​

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Help 41,42

May 17, 2018

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41. cos 300=1/2

May 17, 2018
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42. ?

NotSoSmart  May 17, 2018
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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

May 17, 2018
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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

May 17, 2018
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Thanks!

May 17, 2018