Question

A student said the only fourth root of 16 is 2. describe and correct his error.

Answer 1

see explanation

Explanation:

`\sqrt[4]{16}` = ± 2

since 2 × 2 × 2 × 2 = 16

and - 2 × - 2 × - 2 × - 2 = 4 × 4 = 16

Answer 2

-2 is also a fourth root of 16

Explanation:

2 x 2 x 2 x 2 = 16

But....

-2 x -2 x -2 x -2 also equals 16.

Proof:

-2 x -2 = 4

-2 x 4 = -8

-2 x -8 = 16

Therefore, both 2 and -2 are fourth roots of 16! :)