Problema Solution
Find all complex numbers whose sixth power is equal to 64
Answer provided by our tutors
let 'x' represent the a number whose sixth power is equal to 64
x^6 = 64
x^6 - 64 = 0
factoring the equation we can write:
(x - 2)(x + 2)(x^2 + 2x + 4)(x^2 - 2x + 4) = 0
click here to see the step by step factoring:
the linear factors give two solutions:
x1 = 2
x2 = -2
solving the quadratic factors we find the complex roots:
(x^2 + 2x + 4) = (x + 1)^2 + 3 = (x + 1 + i√3) (x + 1 - i√3)
x3 = -1 - i√3
x4 = -1 + i√3
(x^2 - 2x + 4) = (x - 1)^2 + 3 = (x - 1 + i√3) (x - 1 - i√3)
x5 = 1 - i√3
x6 = 1 + i√3
the complex numbers whose sixth power is equal to 64 are:
1 + i√3, -1 + i√3, 1 - i√3, -1 - i√3