What number multiplied by itself 5 times is -243?

Answer 1

248

Answer 2

A number, x, multiplied by itself once is x^2, not x.

The number, x, multiplied by itself twice is then x^3.

The number, x, multiplied by itself three times is then x^4.

So that the number, x, multiplied by itself five times is x^6, not x^5.

Thus x is the 6th root of -243 and you can use de Moivre's formula to find this complex root.

The six roots are the complex numbers:

2.4980*[sqrt(3)/2 + i/2]

2.4980*[i]

2.4980*[-sqrt(3)/2 + i/2]

2.4980*[-sqrt(3)/2 - i/2]

2.4980*[- i/2]

2.4980*[sqrt(3)/2 - i/2].

Answer 3

It is: -3 because -3^5 = -243