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Comment on Find the Value of Term 4
Brent, with a question like
Thanks
I think that it would only
I think that it would only take a few seconds before you realize that this approach leads nowhere.
That said, the question tells us that the value of term_n depends on the values of term_n-2 and term_n-1. In other words, we need to know the two terms BEFORE term_n in order to calculate term_n.
In other words, this sequence is a recursive (see previous video lesson), which means you can't just plug the require n-value into the formula.
Does that help?
Hi Brent, please may you
Great question!
Great question!
Notice that the value of any term depends on the values of the TWO terms before it.
For example, term7 = 2(term5) - 4(term6)
Likewise, term10 = 2(term8) - 4(term9)
And term13 = 2(term11) - 4(term12)
This also means that term2 = 2(term1) - 4(term0)
Hmm, the sequence starts with term1. So, there is no term0.
Since there is no term0, it doesn't make sense to use the formula (for finding terms) to find term2 and term1.
So, the proviso (n ≥ 3) tells us that the formula only applies to term3, term4, term5, etc.
Does that help?
Cheers,
Brent