AMO 2021 – Junior College (Grades 11–12) Question 2

AMO · AMO 2021 – Junior College (Grades 11–12)

Question 2

If $f(x)=x^3(a\cdot2^x-2^{-x})$ is even, find $a$.

1. $1$
2. $2$
3. $3$
4. $4$
5. $5$