What is the co-efficient of $x^2$ in the expansion of $\left(x+\frac{1}{x^2}\right)^{20}$?
The correct answer should be $605\frac{5}{8}$.
What is the co-efficient of $x^2$ in the expansion of $\left(x+\frac{1}{x^2}\right)^{20}$?
The correct answer should be $605\frac{5}{8}$.
Copyright © 2021 JogjaFile Inc.
It's $$\frac{(x^3+1)^{20}}{x^{40}}$$ and since $x^{42}=(x^3)^{14}$, we get the answer: $\binom{20}{14}$.