## Algebra 2 Common Core

The student was correct in saying that $2$ is a fourth root of $16$ The student was wrong in saying that $2$ is the only fourth root of $16$ because 16 has two real roots: $2$ and $-2$.
The student was right in saying that $2$ is a fourth root of $16$ However, the student was wrong in saying that $2$ is the only fourth root of $16$. Note that $2^4=16 \text{ and} \\(-2)^4=16.$ Thus, 16 has two real fourth roots: $-2$ and $2.$