1952 AMC 12 Question 3
AMC12 · 1952 AMC 12
The expression $a^3-a^{-3}$ equals:
$\left(a-\dfrac1a\right)\left(a^2+1+\dfrac1{a^2}\right)$
$\left(\dfrac1a-a\right)\left(a^2-1+\dfrac1{a^2}\right)$
$\left(a-\dfrac1a\right)\left(a^2-2+\dfrac1{a^2}\right)$
$\left(\dfrac1a-a\right)\left(\dfrac1{a^2}+1+a^2\right)$
None of these