2. The sequence 5, 20, 35, 50….. shows the number of sit ups Margie did each week, starting with her first week of the new year.
(a) What is the recursive rule for the sequence?


(b) What is the explicit rule for the sequence?

Respuesta :

(a) The recursive rule for the sequence is:

     [tex]a_{1}[/tex] = 5 ;  [tex]a_{n}=a_{n-1}+15[/tex]

(b) The explicit rule for the sequence is: [tex]a_{n}=15n-10[/tex]

Step-by-step explanation:

The form of the recursive rule of an arithmetic sequence sequence is

[tex]a_{1}[/tex] = first term ; [tex]a_{n}=a_{n-1}+d[/tex] , where

  • [tex]a_{1}[/tex] is the first term in the sequence
  • [tex]a_{n}[/tex] the nth term in the sequence  
  • [tex]a_{n-1}[/tex] the term before the nth term  
  • n is the term number
  • d is the common difference between each two consecutive terms

The form of the explicit rule of nth term of an arithmetic sequence is

[tex]a_{n}=a+(n-1)d[/tex] , where

  • a is the first term
  • d is the common difference between each two consecutive terms

∵ The sequence is 5, 20, 35, 50, ….......

∵ 20 - 5 = 15 , 35 - 20 = 15 and 50 - 35 = 15

∴ The sequence is an arithmetic sequence with a common

   difference 15

∵ The form of the recursive rule of the arithmetic sequence is

   [tex]a_{1}[/tex] = first term ; [tex]a_{n}=a_{n-1}+d[/tex]

∵ First term = 5

∵ d = 15

∴ [tex]a_{1}[/tex] = 5 ;  [tex]a_{n}=a_{n-1}+15[/tex]

(a) The recursive rule for the sequence is:

     [tex]a_{1}[/tex] = 5 ;  [tex]a_{n}=a_{n-1}+15[/tex]

∵ The form of the explicit rule of nth term of an arithmetic

   sequence is [tex]a_{n}=a+(n-1)d[/tex]

∵ a = 5 and d = 15

- Substitute these values in the rule

∴ [tex]a_{n}=5+(n-1)15[/tex]

- Simplify the right hand side

∴ [tex]a_{n}=5+15n-15[/tex]

- Add like terms

∴ [tex]a_{n}=15n-10[/tex]

(b) The explicit rule for the sequence is [tex]a_{n}=15n-10[/tex]

Learn more;

You can learn more about the sequences in brainly.com/question/3280369

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