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hi i'm Robyn and i'm 13, i am super confused with how you find the nth term with a changing difference, i can totally do it without the changing difference but not with. Especially the formula throws me:
nth term= a+(n-1)d+1/2(n-1)(n-2)c
how would i use it if the sequence was:
2, 4, 7, 11
and I needed to find the 5th term. pleeeeease help Robyn.
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Treat this formula as a function of n:
a, c, and d are constants that we need to solve for. We are given 4 points on this function, though we only need 3 to solve it. Using the given information we know that
You can see from here that a = 2, d = 2, and c = 1, so we're left with
To test this, try n = 4:
which is what we expected. From here you can find any term you need.
Wrap it in bacon
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