# Math Help - sequence

1. ## sequence

Here is the problem:

Define a sequence $c_k$ by the rules
$c_0$ = 2
$c_1$ = 3
$c_k = 0.8c_{k-1} - 0.7c_{k-2}$

Compute $c_2$ through $c_6$

Anyway, I really struggle with these? Where do I start? What process do I go through? Can someone please walk me through this one problem?

Thanks

2. Originally Posted by relyt
Here is the problem:

Define a sequence $c_k$ by the rules
$c_0$ = 2
$c_1$ = 3
$c_k$ = 0.8 $c_k-1$ - 0.7 $c_k-2$

Compute $c_2$ through $c_6$

Those k - 1 and k-2 should be subscripts

Anyway, I really struggle with these? Where do I start? What process do I go through? Can someone please walk me through this one problem?

Thanks
just plug in the values in the $c_k$ formula

example, to find $c_2$, plug in $k = 2$, you get

$c_2 = 0.8c_1 - 0.7c_0 = 0.8(3) - 0.7(2) = 1$

now find the rest the same way

3. Originally Posted by relyt
Here is the problem:

Define a sequence $c_k$ by the rules
$c_0$ = 2
$c_1$ = 3
$c_k = 0.8c_{k-1} - 0.7c_{k-2}$

Compute $c_2$ through $c_6$

Anyway, I really struggle with these? Where do I start? What process do I go through? Can someone please walk me through this one problem?

Thanks
You start by calculating with $k=2$:

$c_2=0.8c_1-0.7c_0=0.8\times 3 - 0.7 \times 2=1$

Now you know $c_0,\ c_1,\ c_2$ proceed to calculate $c_3$, and continue from there.

CB

4. Got it...thank you. That was a lot easier than I thought