Question

A1=11,5, a15=17,2 найти d

Answer 1

An = a1 + d(n - 1)
17,2 = 11,5 +d(15 - 1)
14d = 5,7
d = 57/140

Answer 2

To find the common difference (d) in an arithmetic sequence, we can use the formula:

a_n = a_1 + (n - 1) * d

where a_n is the nth term, a_1 is the first term, n is the position of the term in the sequence, and d is the common difference.

Given that a_1 = 11.5 and a_15 = 17.2, we can substitute these values into the formula to create two equations:

a_1 = 11.5 a_15 = 11.5 + (15 - 1) * d

Substituting the values:

11.5 = 11.5 17.2 = 11.5 + 14 * d

We can solve the second equation for d:

17.2 = 11.5 + 14d 5.7 = 14d d ≈ 0.4071

Therefore, the common difference (d) is approximately 0.4071.