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x^4-5=0

x^4-5=0 equation

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Numerical solution:

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The solution

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 4        
x  - 5 = 0
x45=0x^{4} - 5 = 0
Detail solution
Given the equation
x45=0x^{4} - 5 = 0
Because equation degree is equal to = 4 - contains the even number 4 in the numerator, then
the equation has two real roots.
Get the root 4-th degree of the equation sides:
We get:
(1x+0)44=54\sqrt[4]{\left(1 x + 0\right)^{4}} = \sqrt[4]{5}
(1x+0)44=54\sqrt[4]{\left(1 x + 0\right)^{4}} = - \sqrt[4]{5}
or
x=54x = \sqrt[4]{5}
x=54x = - \sqrt[4]{5}
Expand brackets in the right part
x = 5^1/4

We get the answer: x = 5^(1/4)
Expand brackets in the right part
x = -5^1/4

We get the answer: x = -5^(1/4)
or
x1=54x_{1} = - \sqrt[4]{5}
x2=54x_{2} = \sqrt[4]{5}

All other 2 root(s) is the complex numbers.
do replacement:
z=xz = x
then the equation will be the:
z4=5z^{4} = 5
Any complex number can presented so:
z=reipz = r e^{i p}
substitute to the equation
r4e4ip=5r^{4} e^{4 i p} = 5
where
r=54r = \sqrt[4]{5}
- the magnitude of the complex number
Substitute r:
e4ip=1e^{4 i p} = 1
Using Euler’s formula, we find roots for p
isin(4p)+cos(4p)=1i \sin{\left(4 p \right)} + \cos{\left(4 p \right)} = 1
so
cos(4p)=1\cos{\left(4 p \right)} = 1
and
sin(4p)=0\sin{\left(4 p \right)} = 0
then
p=πN2p = \frac{\pi N}{2}
where N=0,1,2,3,...
Looping through the values of N and substituting p into the formula for z
Consequently, the solution will be for z:
z1=54z_{1} = - \sqrt[4]{5}
z2=54z_{2} = \sqrt[4]{5}
z3=54iz_{3} = - \sqrt[4]{5} i
z4=54iz_{4} = \sqrt[4]{5} i
do backward replacement
z=xz = x
x=zx = z

The final answer:
x1=54x_{1} = - \sqrt[4]{5}
x2=54x_{2} = \sqrt[4]{5}
x3=54ix_{3} = - \sqrt[4]{5} i
x4=54ix_{4} = \sqrt[4]{5} i
The graph
05-15-10-51015-100100
Rapid solution [src]
       4 ___
x_1 = -\/ 5 
x1=54x_{1} = - \sqrt[4]{5}
      4 ___
x_2 = \/ 5 
x2=54x_{2} = \sqrt[4]{5}
         4 ___
x_3 = -I*\/ 5 
x3=54ix_{3} = - \sqrt[4]{5} i
        4 ___
x_4 = I*\/ 5 
x4=54ix_{4} = \sqrt[4]{5} i
Sum and product of roots [src]
sum
 4 ___   4 ___      4 ___     4 ___
-\/ 5  + \/ 5  + -I*\/ 5  + I*\/ 5 
(54)+(54)+(54i)+(54i)\left(- \sqrt[4]{5}\right) + \left(\sqrt[4]{5}\right) + \left(- \sqrt[4]{5} i\right) + \left(\sqrt[4]{5} i\right)
=
0
00
product
 4 ___   4 ___      4 ___     4 ___
-\/ 5  * \/ 5  * -I*\/ 5  * I*\/ 5 
(54)(54)(54i)(54i)\left(- \sqrt[4]{5}\right) * \left(\sqrt[4]{5}\right) * \left(- \sqrt[4]{5} i\right) * \left(\sqrt[4]{5} i\right)
=
-5
5-5
Numerical answer [src]
x1 = 1.49534878122122*i
x2 = -1.49534878122122*i
x3 = 1.49534878122122
x4 = -1.49534878122122
x4 = -1.49534878122122
The graph
x^4-5=0 equation