Which sequence is generated by the function f (n + 1) = f (n) - 2 for f (1) = 10?

*-10, - 12, - 14, - 16, - 18, ...

*-2, 8, 18, 28, 38, ...

*8, 18, 28, 38, 48, ...

*10, 8, 6, 4, 2, ...

F (n+1) = f (n) - 2

f (1) = 10

f (n+1) is the next term after f (n)

we see that the first term is 10

we can imediatel see that the answer is the last option since that is the only one starting with 10

but anyway

f (n+1) = f (n) - 2

to get to the 2nd term, subtract 2 from the first term

10,8,6,4,2,0,-2 ...

last one is the answer

So we're given f (1) right?

f (1) = 10

so that means that f (2) will be:

f (2) = f (1) - 2 since f (1) = 10, plug it in!

f (2) = 10 - 2

f (2) = 8

now f (3):

f (3) = f (2) - 2

f (3) = 8 - 2

f (3) = 6

hence, we see that it is decreasing by two and the only sequence decreasing by two is the last one

answer: 10,8,6,4,2