4th quadrant is positive x (cos) and negative y (sin)
Use the Pythagorean Theorem to calculate the value of y (sin).
x² + y² = c²
5² + y² = 13²
25 + y² = 169
y² = 144
y = 12
Since the y-value is negative in the 4th quadrant, then y = -12
Using the fact that cos is 2π-periodic, we have
That is, 
for any 
and integer 
.
We get 2 solutions in the interval [0, 2π] for 
and 
,
Answer:
Step-by-step explanation:
First you divide the total mulch (77 1/2) by the amount per bag (2 1/4). This will tell you how many bags of mulch you have.
The answer is 34.4444444 which is 34 full bags of mulch.
Now if one bag is $2.25, then what is 34 bags?
$2.25 multiplied by 34 is $76.5
Hope this helps your understanding
