Enter an equation or problem
Camera input is not recognized!

Solution - Finding the roots of polynomials

(a4+9a3+3a2-12)/(a2)
(a^4+9a^3+3a^2-12)/(a^2)

Step by Step Solution

Step  1  :

            12
 Simplify   ——
            a2

Equation at the end of step  1  :

                     12            
  ((((a2) +  11a) -  ——) -  2a) +  3
                     a2            

Step  2  :

Rewriting the whole as an Equivalent Fraction :

 2.1   Subtracting a fraction from a whole

Rewrite the whole as a fraction using  a2  as the denominator :

                 a2 + 11a     (a2 + 11a) • a2
     a2 + 11a =  ————————  =  ———————————————
                    1               a2       

Equivalent fraction : The fraction thus generated looks different but has the same value as the whole

Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator

Step  3  :

Pulling out like terms :

 3.1     Pull out like factors :

   a2 + 11a  =   a • (a + 11) 

Adding fractions that have a common denominator :

 3.2       Adding up the two equivalent fractions
Add the two equivalent fractions which now have a common denominator

Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:

 a • (a+11) • a2 - (12)     a4 + 11a3 - 12
 ——————————————————————  =  ——————————————
           a2                     a2      

Equation at the end of step  3  :

   (a4 + 11a3 - 12)           
  (———————————————— -  2a) +  3
          a2                  

Step  4  :

Rewriting the whole as an Equivalent Fraction :

 4.1   Subtracting a whole from a fraction

Rewrite the whole as a fraction using  a2  as the denominator :

          2a     2a • a2
    2a =  ——  =  ———————
          1        a2   

Polynomial Roots Calculator :

 4.2    Find roots (zeroes) of :       F(a) = a4 + 11a3 - 12
Polynomial Roots Calculator is a set of methods aimed at finding values of  a  for which   F(a)=0  

Rational Roots Test is one of the above mentioned tools. It would only find Rational Roots that is numbers  a  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  -12.

 
The factor(s) are:

of the Leading Coefficient :  1
 
of the Trailing Constant :  1 ,2 ,3 ,4 ,6 ,12

 
Let us test ....

  P  Q  P/Q  F(P/Q)   Divisor
     -1     1      -1.00      -22.00   
     -2     1      -2.00      -84.00   
     -3     1      -3.00      -228.00   
     -4     1      -4.00      -460.00   
     -6     1      -6.00     -1092.00   
     -12     1     -12.00      1716.00   
     1     1      1.00      0.00    a - 1 
     2     1      2.00      92.00   
     3     1      3.00      366.00   
     4     1      4.00      948.00   
     6     1      6.00      3660.00   
     12     1      12.00     39732.00   


The Factor Theorem states that if P/Q is root of a polynomial then this polynomial can be divided by q*x-p Note that q and p originate from P/Q reduced to its lowest terms

In our case this means that
   a4 + 11a3 - 12 
can be divided with  a - 1 

Polynomial Long Division :

 4.3    Polynomial Long Division
Dividing :  a4 + 11a3 - 12 
                              ("Dividend")
By         :    a - 1    ("Divisor")

dividend  a4 + 11a3     - 12 
- divisor * a3   a4 - a3       
remainder    12a3     - 12 
- divisor * 12a2     12a3 - 12a2     
remainder      12a2   - 12 
- divisor * 12a1       12a2 - 12a   
remainder        12a - 12 
- divisor * 12a0         12a - 12 
remainder         0

Quotient :  a3+12a2+12a+12  Remainder:  0 

Polynomial Roots Calculator :

 4.4    Find roots (zeroes) of :       F(a) = a3+12a2+12a+12

     See theory in step 4.2
In this case, the Leading Coefficient is  1  and the Trailing Constant is  12.

 
The factor(s) are:

of the Leading Coefficient :  1
 
of the Trailing Constant :  1 ,2 ,3 ,4 ,6 ,12

 
Let us test ....

  P  Q  P/Q  F(P/Q)   Divisor
     -1     1      -1.00      11.00   
     -2     1      -2.00      28.00   
     -3     1      -3.00      57.00   
     -4     1      -4.00      92.00   
     -6     1      -6.00      156.00   
     -12     1     -12.00      -132.00   
     1     1      1.00      37.00   
     2     1      2.00      92.00   
     3     1      3.00      183.00   
     4     1      4.00      316.00   
     6     1      6.00      732.00   
     12     1      12.00      3612.00   


Polynomial Roots Calculator found no rational roots

Adding fractions that have a common denominator :

 4.5       Adding up the two equivalent fractions

 (a3+12a2+12a+12) • (a-1) - (2a • a2)     a4 + 9a3 - 12
 ————————————————————————————————————  =  —————————————
                  a2                           a2      

Equation at the end of step  4  :

  (a4 + 9a3 - 12)    
  ——————————————— +  3
        a2           

Step  5  :

Rewriting the whole as an Equivalent Fraction :

 5.1   Adding a whole to a fraction

Rewrite the whole as a fraction using  a2  as the denominator :

         3     3 • a2
    3 =  —  =  ——————
         1       a2  

Polynomial Roots Calculator :

 5.2    Find roots (zeroes) of :       F(a) = a4 + 9a3 - 12

     See theory in step 4.2
In this case, the Leading Coefficient is  1  and the Trailing Constant is  -12.

 
The factor(s) are:

of the Leading Coefficient :  1
 
of the Trailing Constant :  1 ,2 ,3 ,4 ,6 ,12

 
Let us test ....

  P  Q  P/Q  F(P/Q)   Divisor
     -1     1      -1.00      -20.00   
     -2     1      -2.00      -68.00   
     -3     1      -3.00      -174.00   
     -4     1      -4.00      -332.00   
     -6     1      -6.00      -660.00   
     -12     1     -12.00      5172.00   
     1     1      1.00      -2.00   
     2     1      2.00      76.00   
     3     1      3.00      312.00   
     4     1      4.00      820.00   
     6     1      6.00      3228.00   
     12     1      12.00     36276.00   


Polynomial Roots Calculator found no rational roots

Adding fractions that have a common denominator :

 5.3       Adding up the two equivalent fractions

 (a4+9a3-12) + 3 • a2     a4 + 9a3 + 3a2 - 12
 ————————————————————  =  ———————————————————
          a2                      a2         

Checking for a perfect cube :

 5.4    a4 + 9a3 + 3a2 - 12  is not a perfect cube

Trying to factor by pulling out :

 5.5      Factoring:  a4 + 9a3 + 3a2 - 12 

Thoughtfully split the expression at hand into groups, each group having two terms :

Group 1:  3a2 - 12 
Group 2:  9a3 + a4 

Pull out from each group separately :

Group 1:   (a2 - 4) • (3)
Group 2:   (a + 9) • (a3)

Bad news !! Factoring by pulling out fails :

The groups have no common factor and can not be added up to form a multiplication.

Polynomial Roots Calculator :

 5.6    Find roots (zeroes) of :       F(a) = a4 + 9a3 + 3a2 - 12

     See theory in step 4.2
In this case, the Leading Coefficient is  1  and the Trailing Constant is  -12.

 
The factor(s) are:

of the Leading Coefficient :  1
 
of the Trailing Constant :  1 ,2 ,3 ,4 ,6 ,12

 
Let us test ....

  P  Q  P/Q  F(P/Q)   Divisor
     -1     1      -1.00      -17.00   
     -2     1      -2.00      -56.00   
     -3     1      -3.00      -147.00   
     -4     1      -4.00      -284.00   
     -6     1      -6.00      -552.00   
     -12     1     -12.00      5604.00   
     1     1      1.00      1.00   
     2     1      2.00      88.00   
     3     1      3.00      339.00   
     4     1      4.00      868.00   
     6     1      6.00      3336.00   
     12     1      12.00     36708.00   


Polynomial Roots Calculator found no rational roots

Final result :

  a4 + 9a3 + 3a2 - 12
  ———————————————————
          a2         

Why learn this

Latest Related Drills Solved