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:
12x² - x - 20 = (4x+5)(3x−4)
9514 1404 393
Answer:
No
Step-by-step explanation:
The initial balance at the beginning of the year is not zero, so the balance is not proportional to the time since the beginning of the year.
__
A proportional relationship always starts at zero when the independent variable is zero.
Answer:
B. 2x – 1 = 13 and x = 7
Step-by-step explanation:
We are given 4 equations and a solution for each. We have to tell which of the given solution satisfies the given equation.
Option A.
2x -1 = 13 and x = 6
Using this value in the equation, we get:
2(6) -1 = 13
12 - 1 = 13
11 = 13, which is not true. Hence this option is not valid
Option B.
2x - 1 = 13 and x = 7
Using the value in the equation, we get:
2(7) - 1 =13
14 - 1 =13
13 = 13, which is true. Hence this option is valid.
Option C.
2x + 1 =13 and x = 7
Using the value in the equation, we get:
2(7) + 1 = 13
15 = 13, which is not true. So this option is not valid
Option D.
2x - 1 = 13 and x = 11
Using this value in the equation, we get:
2(11) - 1 = 13
21 = 13, which is not true. Hence this option is not valid.