Multiple Choice Question (MCQ)
If a_n=\dfrac{(-1)^n}{2n-1}, a_n=
-
×
\dfrac{1}{2}
-
×
\dfrac{1}{5}
-
✓
\dfrac{1}{7}
-
×
\dfrac{1}{9}
Answer
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When n=4
a_n=\dfrac{(-1)^4}{2\times 4 -1}
=\dfrac{1}{7}