Answer:
The equation for the nth term of the given arithmetic sequence is: 
Step-by-step explanation:
We need to write an equation for the nth term of the arithmetic sequence:
15,28,41 ....
The equation for arithmetic sequence is: 
Where
is the nth term,
is first term and d is common difference
In the given sequence we have:
a₁ = 15
a₂ = 28
We can find common difference using the formula:

So, the common difference d is 13
Now, equation for nth term will be:

So, the equation for the nth term of the given arithmetic sequence is: 
where n=1,2,3..
Answer: D. ( -7, - 2 )
Step-by-step explanation:
Rewrite this in vertex form and use this to find the vertex. ( h, k )
By applying the <em>quadratic</em> formula and discriminant of the <em>quadratic</em> formula, we find that the <em>maximum</em> height of the ball is equal to 75.926 meters.
<h3>How to determine the maximum height of the ball</h3>
Herein we have a <em>quadratic</em> equation that models the height of a ball in time and the <em>maximum</em> height represents the vertex of the parabola, hence we must use the <em>quadratic</em> formula for the following expression:
- 4.8 · t² + 19.9 · t + (55.3 - h) = 0
The height of the ball is a maximum when the discriminant is equal to zero:
19.9² - 4 · (- 4.8) · (55.3 - h) = 0
396.01 + 19.2 · (55.3 - h) = 0
19.2 · (55.3 - h) = -396.01
55.3 - h = -20.626
h = 55.3 + 20.626
h = 75.926 m
By applying the <em>quadratic</em> formula and discriminant of the <em>quadratic</em> formula, we find that the <em>maximum</em> height of the ball is equal to 75.926 meters.
To learn more on quadratic equations: brainly.com/question/17177510
#SPJ1