Guest

Ques. If x^5-x^3+x=2 then x^6 belongs to Soln. x(x^4-x^2+1)=2, multiplying by x^2+1 we get x(x^6+1)=2(x^2+1) =>x^6+1=2(x+1/x)>=4 so x^6 belongs to 3 I cant understand how they factorized it and why multiplied with x^2+1 only Thank u

Ques. If x^5-x^3+x=2 then x^6 belongs to


Soln. x(x^4-x^2+1)=2,


multiplying by x^2+1 we get
x(x^6+1)=2(x^2+1)
=>x^6+1=2(x+1/x)>=4


so x^6 belongs to 3<=x

I cant understand how they factorized it and why multiplied with x^2+1 only


Thank u 

Grade:11

1 Answers

Bijoy das
18 Points
10 years ago

hi Swap Bho,

since we need the interval of x^6 , therefore somehow we need to bring a " x^6" term in the given expression in the easiest possible way. Multiplying with x^2+1 to x^4-x^2+1 brings the expression x^6+1 using the identity a^3+b^3. hence solved in this way.  

 

Thank you

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free