

follows from the fact that the cosine function is

-periodic, which means

. Roughly speaking, this is the same as saying that a point on a circle is the same as the point you get by completing a full revolution around the circle (i.e. add

to the original point's angle with respect to the horizontal axis).
If you make another complete revolution (so we're effectively adding

) we get the same result:

. This is true for any number of complete revolutions, so that this pattern holds for any even multiple of

added to the argument. Therefore

for any integer

.
Next, because

, it follows that

is also true for any integer

. So we have

The rest follows from considering either case and solving for

.
Answer:
1469.52
Step-by-step explanation:
V=πr²h
r=6 ft
h=13 ft
π≈3.14
V≈3.14×6²×13 ft³
V≈1469.52 ft³
<h3>
Answer: Choice A. (7,4)</h3>
============================================
Explanation:
Use the slope and given point to find the y intercept
y = mx+b
8 = (-2/3)*(1) + b
8 = -2/3 + b
8 + 2/3 = b
24/3 + 2/3 = b
26/3 = b
b = 26/3
The equation of the line is y = (-2/3)x + 26/3
To confirm this, plug in x = 1 and we should get y = 8, due to the point (1,8)
y = (-2/3)x + 26/3
y = (-2/3)*1 + 26/3
y = -2/3 + 26/3
y = (-2+26)/3
y = 24/3
y = 8
So that verifies we have the correct equation.
--------------
Next, go through each answer choice to see if the x coordinate of the point leads to the y coordinate.
If we try x = 7, then,
y = (-2/3)x + 26/3
y = (-2/3)(7) + 26/3
y = -14/3 + 26/3
y = (-14+26)/3
y = 12/3
y = 4
This shows that (7,4) is on the line. Choice A is the answer
That rules out choice B.
----------------
If we tried x = -5, then,
y = (-2/3)x + 26/3
y = (-2/3)(-5) + 26/3
y = 10/3 + 26/3
y = 36/3
y = 12
meaning that (-5,12) is on the line. That rules out choices C and D.
Refer to the graph below. It visually confirms that of the four answer choices, only point A is on the line. I used GeoGebra to make the graph.
Answer:
b. 12,960ft
Step-by-step explanation:
half of 24 gives you 12 therefore the answer must start from 12.
Answer:
2.5
Step-by-step explanation:
5x+3x=20
8x=20
x=20/8=2.5