Answer: (-2, 11/6)
Step-by-step explanation:
N is an number you make up or your teacher so we need to know what n equals
Step 1: Convert
, which is in radians into degrees. To convert it multiply by 

900/12
75
Step 2: 75 degrees isn't on the unit circle but 45 degrees and 30 degrees is. Since 45 + 30 = 75 you can use the cosine of 45 and 30 to find the exact value
cos45 = 
cos30 =
Step 3: Add the cos45 and cos30 to get cos5pi/12

Hope this helped!
Answer:
29 cans
Step-by-step explanation:
To solve this problem we must use Heron's formula; A = 
S = 1/2 the perimeter of the given triangle
a, b, c = the measurements of the three given sides
The first step to solving this question is first finding the perimeter.
P = 65m + 74m + 67m
P = 206m
Now that we have our perimeter, we must divide P by 2 to get S.
S = 206/2
S = 103
Now we plug our numbers into Heron's formula.
A = 
A = 
A = 
A = 
A = 
Find the square root of this number.
A ≈ 2021.43909134... m²
If a can of paint covers 70 square meters, then you will need to figure out how many cans you need. This can be done by dividing the overall area of the triangle by the area that a single can of paint can cover.
= 28.8777013049...
We know we can't buy 28.87... of a can (people simply do not sell parts of cans or half-full containers... unless its a bag of lays chips and their 80% air nonsense...) so we must round up to the nearest whole number.
28.87... = 29
Thus we finally have our answer: 29 cans of paint!