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z^6=-1

z^6=-1 equation

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Numerical solution:

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The solution

You have entered [src]
 6     
z  = -1
$$z^{6} = -1$$
Detail solution
Given the equation
$$z^{6} = -1$$
Because equation degree is equal to = 6 and the free term = -1 < 0,
so the real solutions of the equation d'not exist

All other 6 root(s) is the complex numbers.
do replacement:
$$w = z$$
then the equation will be the:
$$w^{6} = -1$$
Any complex number can presented so:
$$w = r e^{i p}$$
substitute to the equation
$$r^{6} e^{6 i p} = -1$$
where
$$r = 1$$
- the magnitude of the complex number
Substitute r:
$$e^{6 i p} = -1$$
Using Euler’s formula, we find roots for p
$$i \sin{\left(6 p \right)} + \cos{\left(6 p \right)} = -1$$
so
$$\cos{\left(6 p \right)} = -1$$
and
$$\sin{\left(6 p \right)} = 0$$
then
$$p = \frac{\pi N}{3} + \frac{\pi}{6}$$
where N=0,1,2,3,...
Looping through the values of N and substituting p into the formula for w
Consequently, the solution will be for w:
$$w_{1} = - i$$
$$w_{2} = i$$
$$w_{3} = - \frac{\sqrt{3}}{2} - \frac{i}{2}$$
$$w_{4} = - \frac{\sqrt{3}}{2} + \frac{i}{2}$$
$$w_{5} = \frac{\sqrt{3}}{2} - \frac{i}{2}$$
$$w_{6} = \frac{\sqrt{3}}{2} + \frac{i}{2}$$
do backward replacement
$$w = z$$
$$z = w$$

The final answer:
$$z_{1} = - i$$
$$z_{2} = i$$
$$z_{3} = - \frac{\sqrt{3}}{2} - \frac{i}{2}$$
$$z_{4} = - \frac{\sqrt{3}}{2} + \frac{i}{2}$$
$$z_{5} = \frac{\sqrt{3}}{2} - \frac{i}{2}$$
$$z_{6} = \frac{\sqrt{3}}{2} + \frac{i}{2}$$
The graph
Sum and product of roots [src]
sum
                 ___         ___     ___             ___
           I   \/ 3    I   \/ 3    \/ 3    I   I   \/ 3 
-I + I + - - - ----- + - - ----- + ----- - - + - + -----
           2     2     2     2       2     2   2     2  
$$\left(- i\right) + \left(i\right) + \left(- \frac{\sqrt{3}}{2} - \frac{i}{2}\right) + \left(- \frac{\sqrt{3}}{2} + \frac{i}{2}\right) + \left(\frac{\sqrt{3}}{2} - \frac{i}{2}\right) + \left(\frac{\sqrt{3}}{2} + \frac{i}{2}\right)$$
=
0
$$0$$
product
                 ___         ___     ___             ___
           I   \/ 3    I   \/ 3    \/ 3    I   I   \/ 3 
-I * I * - - - ----- * - - ----- * ----- - - * - + -----
           2     2     2     2       2     2   2     2  
$$\left(- i\right) * \left(i\right) * \left(- \frac{\sqrt{3}}{2} - \frac{i}{2}\right) * \left(- \frac{\sqrt{3}}{2} + \frac{i}{2}\right) * \left(\frac{\sqrt{3}}{2} - \frac{i}{2}\right) * \left(\frac{\sqrt{3}}{2} + \frac{i}{2}\right)$$
=
1
$$1$$
Rapid solution [src]
z_1 = -I
$$z_{1} = - i$$
z_2 = I
$$z_{2} = i$$
              ___
        I   \/ 3 
z_3 = - - - -----
        2     2  
$$z_{3} = - \frac{\sqrt{3}}{2} - \frac{i}{2}$$
            ___
      I   \/ 3 
z_4 = - - -----
      2     2  
$$z_{4} = - \frac{\sqrt{3}}{2} + \frac{i}{2}$$
        ___    
      \/ 3    I
z_5 = ----- - -
        2     2
$$z_{5} = \frac{\sqrt{3}}{2} - \frac{i}{2}$$
            ___
      I   \/ 3 
z_6 = - + -----
      2     2  
$$z_{6} = \frac{\sqrt{3}}{2} + \frac{i}{2}$$
Numerical answer [src]
z1 = 0.866025403784439 + 0.5*i
z2 = -0.866025403784439 - 0.5*i
z3 = -0.866025403784439 + 0.5*i
z4 = 1.0*i
z5 = 0.866025403784439 - 0.5*i
z6 = -1.0*i
z6 = -1.0*i
The graph
z^6=-1 equation