really need help!

Question

explain why ³√-64 is real but √-64 is not

Answer 1

³√(-64) = -4, since (-4)³ = -64

 

If x = √(-64), then x² = -64.

 

     If x is real, then x²≥0.

 

     So, the equation x² = -64 has no real solutions.