Answer:
D) cot(C) = 1/2.
Step-by-step explanation:
We can go through each choice and examine is validity.
Choice A)
We have:

Recall that secant is the ratio of the hypotenuse to the adjacent.
With respect to B, the adjacent is 6 and the hypotenuse is 7.
Therefore, sec(B) should be 7/6 instead.
A is incorrect.
Choice B)
We have:

Cotangent is the ratio of the adjacent side to the opposite.
With respect to B, the adjacent side is 6 and the opposite side is 3.
Therefore, cot(B) = 6/3 = 2.
B is incorrect.
Choice C)
C is incorrect for the reasons listed in A.
Choice D)
We have:

Again, cotangent is the ratio of the adjacent side to the opposite.
With respect to C, the adjacent side is 3 and the opposite side is 6.
So, cot(C) = 3/6 = 1/2.
Therefore, D is the correct choice!
Answer:
155v^4
Step-by-step explanation:
Answer:
4.66
Step-by-step explanation:
We are given the following data
26, 26, 21, 22, 20, 25, 35
Step 1
We find the Mean
Mean = 26+ 26+ 21+ 22+20+25+ 35/7
= 175/7
= 25
Step 2
We find the Standard Deviation
The formula for Standard deviation that we would use is the Population Standard deviation, this is because the data given above is the data of the number of pounds of trash collected by each teenager
= √(x - Mean)²/n
= √(26 - 25)²+( 26 - 25)²+ (21 - 25)²+ (22 - 25)² +(20 - 25)²+(25 - 25)²+ (35 - 25)²/7
= √152/7
= √21.7142857
= 4.65985898
Approximately = 4.66
Answer:

Step-by-step explanation:
The question we have at hand is, in other words,
- where we have to solve for the value of 
If we have to isolate
here, then we would have to take the inverse of the following matrix ...
... so that it should be as follows ... 
Therefore, we can conclude that the equation as to solve for "
" will be the following,
- First find the 2 x 2 matrix inverse of the first portion,
=
=
=
At this point we have to multiply the rows of the first matrix by the rows of the second matrix,
,
- Simplifying this, we should get ...
... which is our solution.
So the number of pencils bought can be represented by an equation:

, where n is the number of notebooks bought. Since Helen bought 5 notebooks, simply plug 5 into n:

. So Helen bought 12 pencils.