First of, I know this is quite easy but I can't really work it out.
I need find the rule for these sequences
$a.$ $2, 3, 4.5, 6.25…$
$b$ $54, 18, 6, 2…$
$c$ $0.01, 0.1, 1, 10…$
My Steps
What I did first was find the differences between the numbers.
For question $a$ the difference between numbers goes $1$, $1.5$, $1.75$
For question $b$ the differnce between numbers goes $-36$, $-12$, $-4$. In this sequence I have found out that the number is being divided by $3$.
For question $c$ the difference between numbers goes $+0.09$, $+0.9$, $+9$. In this the term $9$ is being multiplied by $10$.
I am not sure what to do after. I can do the $nth$ term when it comes to numbers that go up the same and also squared, cubed and triangle numbers.
I know the general formula for $nth$ term is:
nth term = difference x n + (first term – difference).
I can't really use it though as the difference varies. Thanks!
Best Answer
Instead of differences, try the quotients between consecutive terms.