<h3>
Answer:</h3>
- left picture (bottom expression): -cot(x)
- right picture (top expression): tan(x)
<h3>
Step-by-step explanation:</h3>
A graphing calculator can show you a graph of each expression, which you can compare to the offered choices.
_____
You can make use of the relations ...
... sin(a)+sin(b) = 2sin((a+b)/2)cos((a-b)/2)
... cos(a)+cos(b) = 2cos((a+b)/2)cos((a-b)/2)
... cos(a)-cos(b) = -2sin((a+b)/2)sin((a-b)/2)
Then you have ...

and ...

The range of communication is about 55 meters.
Answer:
Step-by-step explanation:
Simplifying
2x + 13 = 0
Reorder the terms:
13 + 2x = 0
Solving
13 + 2x = 0
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-13' to each side of the equation.
13 + -13 + 2x = 0 + -13
Combine like terms: 13 + -13 = 0
0 + 2x = 0 + -13
2x = 0 + -13
Combine like terms: 0 + -13 = -13
2x = -13
Divide each side by '2'.
x = -6.5
Simplifying
x = -6.5
Answer:
16.2 ft
Step-by-step explanation:
Answer:
7+3(-4)(2) -2[12/(-3)] (15-7)-(9/3) -5[7+(-14)]-30= 49
Step-by-step explanation: