Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.



Question

|
One Answer Below

Anyone can contribute an answer, even non-tutors.

Answer This Question
Mary
Mary

Secondary 1 chevron_right Maths chevron_right Hong Kong

General term of sequence
2,-4,6,-8,10,...

Date Posted: 5 years ago
Views: 507
J
J
5 years ago
General term = (-1)^(n+1)2n
= -2n(-1)ⁿ

See 1 Answer

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Kam Tian Qiao
Kam Tian Qiao's answer
14 answers (Tutor Details)
1st
From the question you can observe that , the number increase by 2 , and the sign is alternating , so number increase by 2 can be represent by 2n , and alternating sign can represent by (-1)^n , combine both u get 2n*(-1)^n , substitute n =1,2,3,4 into it u get -2,+4,-6,+8 right? So add negative sign to it ,becomes -2n*(-1)^n , therefore u will get +2,-4,+6,-8 when substitute n=1,2,3,4