Step-by-step explanation:
Initially, there's only 1 letter.
Tania sends the letter to 4 friends.
Each friend sends a letter to 4 more friends (4 × 4 = 16).
Each of those friends sends to 4 more friends (16 × 4 = 64).
The pattern is 1, 4, 16, 64, etc.
This is a geometric sequence. The first term is 1 and each term is 4 times the previous term.
a₁ = 1
aₙ = 4 aₙ₋₁
The explicit formula is:
aₙ = 1 (4)ⁿ⁻¹
In general, the dependent variable will be by itself on the left side of the equation. Its value depends upon that of the independent variable embedded in some expression on the right side.
The <em>twelfth</em> element of the <em>geometric</em> sequence is equal to 4,096. (Correct choice: D)
<h3>How to find a determined element of a geometric sequence by exponential formulae</h3>
Sequences are series of elements generated according to at least one condition, usually equations. <em>geometric</em> sequences are generated according to a <em>exponential</em> formulas, whose form and characteristics are described below:
f(n) = a · bⁿ ⁻ ¹ (1)
Where:
- a - First element of geometric sequence
- b - Common ratio of the geometric sequence
- n - Element index within the geometric sequence
If we know that a = 4, b = 2 and n = 12, then the twelfth element of the geometric sequence from the statement is:
f(12) = 4 · 2¹² ⁻ ¹
f(12) = 4 · 2¹¹
f(12) = 4 · 2,048
f(12) = 4,096
The <em>twelfth</em> element of the <em>geometric</em> sequence is equal to 4,096. (Correct choice: D)
To learn more on geometric sequences: brainly.com/question/4617980
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Answer:
The equivalent to -(-5.25) = 5.25
Step-by-step explanation:
Given
We need to determine the equivalent to -(-5.25)
some of the sign rules are:
+(+) = +
−(−) = +
+(−) = -
−(+) = -
Thus,
Applying the rule: -a(-a) = a
Therefore, the equivalent to -(-5.25) = 5.25
