Find an equation for the nth term of the arithmetic sequence. -1, 2, 5, 8, ...
2 answers:
Answer:
The expression for the n-th term is
Step-by-step explanation:
We know that the n-th term of an arithmetic progression is given by . So we need to find the coefficients
and
. In order to do this, we substitute the values
and
in the expression for
:
Now, notice that we have two linear equations with two unknowns, which it is not difficult to solve. Thus, the solution is and
.
Hence, the expression for the n-th term is
We can check that the expression is correct substituting the values which gives
and
which gives
, as it is given in the statement of the problem.
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