The main identity you need is the double angle one for cosine:

We get

Expand the numerator to apply the identity again:




Finally, make use of the product identity for cosine:

so that ultimately,


Answer:
3x^2 is the final solution
See the image below for step by step explanation.
There are 1760 yards in a mile. 1760 x 3 = 5280
Hope this helped!
Answer:
I think it's 7
Step-by-step explanation:
-6 < 2T (-5+5) < 3+5
-6 < 2T < 8
+6 < 2T < 8 + 6
0 < 2T < 14
0 < ÷ 2 < ÷ 2
0 < T < 7
-0 < T < -0
T = 7
Let x be the price for each night and y be the price for each meal. Then, express the statements into mathematical equations:
Choice A: 3x + y = 250
Choice B: 3x + 6y = 330
Subtract both equations, the difference would be -5y = -80
-5y = -80
y = -80/-5
y = $16 per meal
3x + y = 250
3x + 16 = 250
3x = 250 - 16
3x = 234
x = 234/3
x = $78 per night
The answer is D.