Question
Question: The co-efficient of y in the expansion of (y<sup>2</sup> 2+c/y)<sup>5</sup> is...
The co-efficient of y in the expansion of (y2 2+c/y)5 is
A
10 c3
B
20 c2
C
10 c
D
20 c
Answer
10 c3
Explanation
Solution
General term in the expansion =$5C_{r}\left( y^{2} \right)^{\begin{matrix} \
\end{matrix}r}\left( \frac{c}{y} \right)^{5 - r}$
=5Cry3r−5c5−r
For coefficient of y, put r = 2