Difference equations

[Schirelle]

For the difference equations, express tn in terms of n.
A) tn+1=2tn,t1=5

[kamil9876]

You really mean, right?

In that case since to get from one to the next you multiply by 2, hence to get from t_1 to t_n you multiply n-1 times.

[Schirelle]

Thankyou! This helped me so much!

[lala1911]

kamil9876, is that 5 x 2?

[Yacoubb]

For the difference equations, express tn in terms of n.
A) tn+1=2tn,t1=5

Okay, so first you establish that this is a Geometric Sequence. (r>1 and d=0).

So:
a = 5
r = 2
n = n

Tn = a x r^n-1
= 5 x 2^n-1

And that's your answer. Its all about identifying whether it is geometric/arithmetic/neither and then applying the appropriate formula.