square root of 81: √81

The square root of 81 (√81) is 9.

square root of 100: √100

The square root of 100 (√100) is 10.

cube root of 512: √^3 512

The cube root of 512 (³√512) is 8.

cube root of -343

The cube root of -343 (³√-343) is -7.

cube root of 81

The cube root of 81 (³√81) is 4.

wrong