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
The radius of the cylinder would be 17.99544
D and E
the triangle is right as it has a right angle as one of the 3 angles
the triangle is isosceles as it has 2 equal sides , indicated by the score on the equal sides and 2 equal base angles of 45°
The answer is -10 x -9, -8, -7, -6 etc
The true statement about the function f(x) = -x² - 4x + 5 is that:
- The range of the function is all real numbers less than or equal to 9.
<h3 /><h3>What is the domain and range for the function of y = f(x)?</h3>
The domain of a function is the set of given values of input for which the function is valid and true.
The range is the dependent variable of a given set of values for which the function is defined.
- The domain of the function: f(x) = -x² - 4x + 5 are all real number from -∞ to +∞
For a parabola ax² + bx + c with the vertex 
- If a < 0, then the range is f(x) ≤

- If a > 0, then the range f(x) ≥

The vertex for an up-down facing parabola for a function y = ax² + bx + c is:

Thus,
- vertex
= (-2, 9)
Range: f(x) ≤ 9
Therefore, we can conclude that the range of the function is all real numbers less than or equal to 9.
Learn more about the domain and range of a function here:
brainly.com/question/26098895
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