Question

what is the nth term of the quadratic sequence: 8,16,26,38,52,68,86?

Answer 1

Answer: this is the answer of your above questionnaire=a

Step-by-step explanation:

Answer 2

The nth term of the given quadratic sequence is ,

$u_n=n^2-5n-12c$

Given-

The given sequence in the problem is,

$8,16,26,38,52,68,86.$

The First difference series of the above sequence is.

$8,10,12,14,16,18$

The second difference series of the above sequence is.

$2,2,2,2,2,2,2$

The formula to find the nth term for the quadratic  series can be given as,

$u_n=an^2+bn+c$

Here, to find out the $a$ divide the second difference with 2, we get,

$a=\dfrac{2}{2} =1$

so the first term of the nth term is $1n^2$. Put the values of n in this first term as,

$n=1,2,3,4,5$

We get,

$1n^2=1+4+9+16+25$

Difference of the above series is,

$-7,-12,-17,-22,-27$

Now the nth term of this sequence (-7,-12,-17,-22,-27) is -5n-12. Thus b is -5 and c is-12.

Hence The nth term of the given quadratic sequence is ,

$u_n=n^2-5n-12c$

For more about the quadratic sequence , follow the link below-

https://brainly.com/question/11323348