SOLUTION: FInd the quadratic equation each of whose roots is the sum of a root and its reciprocal of the quadratic equation 2x^2 + 3x + 4 = 0.

Algebra.Com
Question 1183896: FInd the quadratic equation each of whose roots is the sum of a root and its reciprocal of the quadratic equation 2x^2 + 3x + 4 = 0.
Answer by ikleyn(52777)   (Show Source): You can put this solution on YOUR website!
.
FInd the quadratic equation each of whose roots is the sum of a root
and its reciprocal of the quadratic equation 2x^2 + 3x + 4 = 0.
~~~~~~~~~~~~~~~~~~~


            You are talking about another interpretation of the problem, previously solved.
            This interpretation is slightly different problem, but still very close to the previous one.
            It can be solved using the same method and metodology.
            Again, this problem is to apply the  Vieta's theorem several times.


Let  " a "  and  " b "  be the roots of the given equation.


Then according to Vieta's theorem, the sum  (a+b)  is equal to   :  a + b = .

According to the same theorem, the product of the routs  ab  is equal to   = 2.



OK.  



HENCE, the projected equation has the value  A =   as one of its roots, and has the value B =   as the another root.


The sum of the roots A + B is  A + B =  =  = .


We substitute here  a+b =   and  ab = 2,  and we get  A + B =  +  =  = .



Next, A*B =  =  = 2 +  +  = 2  +  = 2  +  = 

          = 2  +  = 2  +  = 2  +  = 2  -  =  -  = .


HENCE, applying the Vieta's theorem again, the projected equation has the form


    x^2 - (A+B)x + AB = 0,   or    = 0.


You can have this equation with integer coefficient by multiplying its terms by 8.  You will get then the final equation as


     = 0.

Solved.

--------------

As I said,  the same methodology works.

I think,  that after my previous solution,  an advanced student would be able to solve this one  ON  HIS  OWN.

In any case,  I am glad to hear your response,  which was meaningful,  what  RARELY  HAPPENS  at this forum.



RELATED QUESTIONS

FInd the quadratic equation each of whose roots is the sum of a root and its reciprocal... (answered by ikleyn)
find the quadratic equation whose roots is; square root of the roots of... (answered by Theo)
Write a quadratic equation with leading coefficient of 1 having as its two roots the... (answered by ankor@dixie-net.com)
Given that the quadratic equation x^2-2x-5=0 has 2 different roots, and a second... (answered by mananth)
Given that the quadratic equation x^2-3x+1=0 has 2 different roots, create a quadratic... (answered by josh_jordan)
form a quadratic equation in x whose roots are the squares of the roots of... (answered by MathLover1)
What is the sum of the roots of the quadratic equation... (answered by checkley71)
Determine the quadratic equation whose roots have a sum of 12 and the roots difference is (answered by richwmiller,Alan3354,MathTherapy)
Write the quadratic equation with a lead coefficient of 1 whose roots are 2+ square root... (answered by Nate)