Question

Which is the correct recursive formula for this sequence? -7, -5.6, -4.2, -2.8, -1.4, ....

recursive: an = an – 1 + 1.4, where a1 = –7

OR

recursive: an = an – 1 + 1.4n, where a1 = –7

?

I tried plugging the numbers into the equation, but couldn't get any option other than 1.4.

Please write it in equation form so I can see. Thanks.

Answer 1

The first 1:
a(n)=a(n-1)+1.4
a(0)=-7
a(1)=-7+1.4=-5.6
a(2)=-5.6+1.4=-4.2
...