The first term of the geometric sequence is 0.0061
<u>Step-by-step explanation:</u>
The general form of geometric sequence is a, ar, ar²,ar³,.......
where,
- a is the first term of the sequence.
- r is the common ratio. Here, the common ratio r = 4.
- The 8th term of the sequence is 100. Hence n = 8.
<u>The formula to find the nth term of the geometric sequence is given by :</u>
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
⇒ a = 0.0061
Therefore, the first term of the geometric sequence is 0.0061
-0.15 is the correct answer I suppose!
Recall that the discriminant is b² - 4ac
So, substitute, b = 4, a = -1 and c = -2
Δ = 16 - 4(-1)(-2) = 16 - 8 = 8