ANSWER
-2 shift the graph of the basic function down by 2 units.
EXPLANATION
The given cosine function is:

This equation can be rewritten as:

We compare this to

The effect d has on the graph is that, it shifts the graph up by d units.
If d is negative the graph shifts down by d units.
Since d=-2, the graph will shift down by 2 units.
Answer:
2x + 8
Step-by-step explanation:
This is the pattern:
y is 2 times x plus 8
Write this relationship as an equation.
y=2x+8
An = a1 + (n-1) * d
a12 = 47 + (12 - 1) * -5
a12 = 47 + 11 * -5
a12 = 47 - 55
a12 = - 8 <==
The answer is the first one, (2)
The answer is all real numbers because -2x-6=-2x-6