Answer:

Step-by-step explanation:
Given

Required
Determine an equivalent expression
In trigonometry:

In 

Substitute
for
in 


Hence, the equivalent expression is: 
Answer:
10.7 m
Step-by-step explanation:
Given that,
The speed of a sound wave, v = 6,420 m/s
The frequency of the wave, f = 600 Hz
We need to find the wavelength of the wave. We can find it using the below relation as follows :

So, the wavelength of the sound wave is equal to 10.7 m.
Answer:
Part I: cot(15 degrees) = cot(45 - 30)
Part II: Evaluation is below
Step-by-step explanation:
<em>Everything is done in degrees</em>
<em />
Two angles that differ by 15 degrees that is easy to evaluate is 30 degrees and 45 degrees. The cot(15 degrees) = cot(45 - 30) = 1/tan(45-30) = (1+tan45tan30)/(tan30 - tan45) = (1+ sqrt(3))/(sqrt(3) - 1)
We rationalize this by multiplying 1+ sqrt(3) in the top and bottom, getting:
(4 + 2sqrt(3))/2 = 2 + sqrt(3)
I hope this helps! :)
Answer:
y = 14
Step-by-step explanation:
move 5y over to the left and you should get -2y +6=-18. subtract 6from both sides and you will now have -2y=-24. divide bothe sides from -2 and you will get y=14