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Solution - Simplifying radicals

x=6*root[3]6=10.9027
x=6*root[3]{6}=10.9027

Other Ways to Solve

Simplifying radicals

Step by Step Solution

Rearrange:

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

                     x^3-(1296)=0 

Step by step solution :

Step  1  :

Trying to factor as a Difference of Cubes:

 1.1      Factoring:  x3-1296 

Theory : A difference of two perfect cubes,  a3 - b3 can be factored into
              (a-b) • (a2 +ab +b2)

Proof :  (a-b)•(a2+ab+b2) =
            a3+a2b+ab2-ba2-b2a-b3 =
            a3+(a2b-ba2)+(ab2-b2a)-b3 =
            a3+0+0-b3 =
            a3-b3


Check :  1296  is not a cube !!
Ruling : Binomial can not be factored as the difference of two perfect cubes

Polynomial Roots Calculator :

 1.2    Find roots (zeroes) of :       F(x) = x3-1296
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  1  and the Trailing Constant is  -1296.

 
The factor(s) are:

of the Leading Coefficient :  1
 
of the Trailing Constant :  1 ,2 ,3 ,4 ,6 ,8 ,9 ,12 ,16 ,18 , etc

 
Let us test ....

  P  Q  P/Q  F(P/Q)   Divisor
     -1     1      -1.00     -1297.00   
     -2     1      -2.00     -1304.00   
     -3     1      -3.00     -1323.00   
     -4     1      -4.00     -1360.00   
     -6     1      -6.00     -1512.00   


Note - For tidiness, printing of 15 checks which found no root was suppressed

Polynomial Roots Calculator found no rational roots

Equation at the end of step  1  :

  x3 - 1296  = 0 

Step  2  :

Solving a Single Variable Equation :

 2.1      Solve  :    x3-1296 = 0 

 
Add  1296  to both sides of the equation : 
 
                     x3 = 1296
When two things are equal, their cube roots are equal. Taking the cube root of the two sides of the equation we get:  
 
                     x  =  ∛ 1296  

 
Can  ∛ 1296 be simplified ?

Yes!   The prime factorization of  1296   is
   2•2•2•2•3•3•3•3 
To be able to remove something from under the radical, there have to be  3  instances of it (because we are taking a cube i.e. cube root).

1296   =  ∛ 2•2•2•2•3•3•3•3   =2•3•∛ 6   =
                6 • ∛ 6


The equation has one real solution
This solution is  x = 6 • ∛6 = 10.9027

One solution was found :

                   x = 6 • ∛6 = 10.9027

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