Solution - Nonlinear equations

Reformatting the input :

Changes made to your input should not affect the solution:

 (1): "x7"   was replaced by   "x^7". 

Rearrange:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :

                     0-(2*x^2-8*x^7)=0 

Step by step solution :

Step  1  :

Equation at the end of step  1  :

  0 -  ((2 • (x2)) -  23x7)  = 0 
 Step  2  :

Equation at the end of step  2  :

  0 -  (2x2 -  23x7)  = 0 

Step  3  :

Step  4  :

Pulling out like terms :

 4.1     Pull out like factors :

   -2x² + 8x⁷  =   2x² • (4x⁵ - 1) 

Polynomial Roots Calculator :

 4.2    Find roots (zeroes) of :       F(x) = 4x⁵ - 1
Polynomial Roots Calculator is a set of methods aimed at finding values of  x  for which   F(x)=0  

Rational Roots Test is one of the above mentioned tools. It would only find Rational Roots that is numbers  x  which can be expressed as the quotient of two integers

The Rational Root Theorem states that if a polynomial zeroes for a rational number  P/Q   then  P  is a factor of the Trailing Constant and  Q  is a factor of the Leading Coefficient

In this case, the Leading Coefficient is  4  and the Trailing Constant is  -1.

 The factor(s) are:

of the Leading Coefficient :  1,2 ,4
 of the Trailing Constant :  1

 Let us test ....

Polynomial Roots Calculator found no rational roots

Equation at the end of step  4  :

  2x2 • (4x5 - 1)  = 0 

Step  5  :

Theory - Roots of a product :

 5.1    A product of several terms equals zero. 

 When a product of two or more terms equals zero, then at least one of the terms must be zero. 

 We shall now solve each term = 0 separately 

 In other words, we are going to solve as many equations as there are terms in the product 

 Any solution of term = 0 solves product = 0 as well.

Solving a Single Variable Equation :

 5.2      Solve  :    2x² = 0 

 Divide both sides of the equation by 2:
                     x² = 0
 
 When two things are equal, their square roots are equal. Taking the square root of the two sides of the equation we get:  
                      x  =  ± √ 0  

 Any root of zero is zero. This equation has one solution which is  x = 0

Solving a Single Variable Equation :

 5.3      Solve  :    4x⁵-1 = 0 

 Add  1  to both sides of the equation : 
                      4x⁵ = 1
Divide both sides of the equation by 4:
                     x⁵ = 1/4 = 0.250
                     x  =  5th root of (1/4) 

 The equation has one real solution
This solution is  x = 5th root of ( 0.250) = 0.75786

Two solutions were found :

1.  x = 5th root of ( 0.250) = 0.75786
2.  x = 0