This is a geometric sequence with first term 1 and common ratio -1/2. r=-1/2.
a(n) = a(1)*(r)^(n-1).
Check: If n=2 our formula must return -1/2. Does it?
a(2) = 1(-1/2)^(2-1) = (-1/2)^1 = - 1/2. Yes.
a(3) should be 1/4. Is it? a(3) = (-1/2)^(3-1) = 1/4 Yes.
Then a(8) = (-1/2)^(8-1) = (-1/2)^7 = -1 / 2^7 = -1/128 (answer)
Answer:
b
Step-by-step explanation:
Answer:
The area of the regular octagon is 
Step-by-step explanation:
we know that
The area of the regular polygon is equal to

where
P is the perimeter of the regular polygon
a is the apothem
<em>Find the perimeter P</em>

Find the area

Answer: The answer would be 8.5 times 10^-5
Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the
10 If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.