Answer:
The decibel range is 
Step-by-step explanation:
Let
d -----> the decibel level of the music
we know that
The absolute value of the difference of the decibel level of the music and its average, must be less than or equal to 28 decibels
so
The absolute value that represent this problem is

Solve the absolute value
<em>First solution (positive)</em>

Adds 110 both sides


<em>Second solution (negative)</em>

Multiply by -1 both sides

Adds 110 both sides


therefore
The decibel range is

Answer:
The answer would be 346
Step-by-step explanation:
Hope this helps!
Answer: 
Step-by-step explanation:
The figure is formed by a square, a parallelogram and a rectangle.
Then, the area of the figure will be the sum of the area of the square, the area of the parallelogram and the area of the rectangle.
The area of the square is:
The area of the parallelogram is:
The area of the rectangle is:
Therefore, the area of the figure is:

9514 1404 393
Answer:
1. (a) -√5
2. 3/5
Step-by-step explanation:
1. sec²(θ) = tan²(θ) +1
sec²(θ) = (-2)² + 1 = 5
sec(θ) = ±√5
In the second quadrant, secant is negative, so ...
sec(θ) = -√5
__
2. cos(θ) = 1/sec(θ)
cos(θ) = 1/(5/3)
cos(θ) = 3/5