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z-4-4z-3-6z-2-4z-1-z-4-4z-3-6z-2-4z-1-z-1-z-1-Find-z-R-




Question Number 203474 by ajfour last updated on 20/Jan/24
((z^4 +4z^3 −6z^2 −4z+1)/(z^4 −4z^3 −6z^2 +4z+1))=((z+1)/(z−1))  Find z∈R.
z4+4z36z24z+1z44z36z2+4z+1=z+1z1FindzR.
Answered by Rasheed.Sindhi last updated on 20/Jan/24
Using Componendo-Dividendo  (((z^4 +4z^3 −6z^2 −4z+1)+(z^4 −4z^3 −6z^2 +4z+1))/((z^4 +4z^3 −6z^2 −4z+1)−(z^4 −4z^3 −6z^2 +4z+1)))               =(((z+1)+(z−1))/((z+1)−(z−1)))   ((2z^4 −12z^2 +2)/(8z^3 −8z))=((2z)/2)  ((z^4 −6z^2 +1)/(4z^3 −4z))=z  z^4 −6z^2 +1=4z^4 −4z^2   3z^4 +2z^2 −1=0  (z^2 +1)(3z^2 −1)=0  z^2 =−1,(1/3)  z=±i,  ±(1/( (√3)))  ✓
UsingComponendoDividendo(z4+4z36z24z+1)+(z44z36z2+4z+1)(z4+4z36z24z+1)(z44z36z2+4z+1)=(z+1)+(z1)(z+1)(z1)2z412z2+28z38z=2z2z46z2+14z34z=zz46z2+1=4z44z23z4+2z21=0(z2+1)(3z21)=0z2=1,13z=±i,±13
Answered by Rasheed.Sindhi last updated on 20/Jan/24
Using Cross Multiplication  ▶z^5 +4z^4 −6z^3 −4z^2 +z−z^4 −4z^3 +6z^2 +4z−1       =z^5 −4z^4 −6z^3 +4z^2 +z+z^4 −4z^3 −6z^2 +4z+1  ▶8z^4 −2z^4 +4z^2 −2=0  ▶3z^4 +2z^2 −1=0  ▶(z^2 +1)(3z^2 −1)=0  ▶ z^2 =−1,(1/3)  ▶z=±i, ±(1/( (√3))) ✓
UsingCrossMultiplicationz5+4z46z34z2+zz44z3+6z2+4z1=z54z46z3+4z2+z+z44z36z2+4z+18z42z4+4z22=03z4+2z21=0(z2+1)(3z21)=0z2=1,13z=±i,±13
Answered by Rasheed.Sindhi last updated on 20/Jan/24
((z^4 +4z^3 −6z^2 −4z+1)/(z^4 −4z^3 −6z^2 +4z+1))=((k(z+1))/(k(z−1))) (let)  where k is such that:   { ((z^4 +4z^3 −6z^2 −4z+1=k(z+1))),((                          &)),((z^4 −4z^3 −6z^2 +4z+1=k(z−1))) :}    { ((z^4 +4z^3 −6z^2 −4z+1−kz−k=0)),((z^4 −4z^3 −6z^2 +4z+1−kz+k=0)) :}   Adding & Subtracting:   { ((z^4 −6z^2 −kz+1=0)),((4z^3 −4z−k=0⇒k=4z^3 −4z)) :}  ⇒z^4 −6z^2 −(4z^3 −4z)z+1=0  z^4 −6z^2 −4z^4 +4z^2 +1=0  3z^4 +2z^2 −1=0  (z^2 +1)(3z^2 −1)=0  z^2 =−1,(1/3)  z=±i, ±((√3)/3) ✓
z4+4z36z24z+1z44z36z2+4z+1=k(z+1)k(z1)(let)wherekissuchthat:{z4+4z36z24z+1=k(z+1)&z44z36z2+4z+1=k(z1){z4+4z36z24z+1kzk=0z44z36z2+4z+1kz+k=0Adding&Subtracting:{z46z2kz+1=04z34zk=0k=4z34zz46z2(4z34z)z+1=0z46z24z4+4z2+1=03z4+2z21=0(z2+1)(3z21)=0z2=1,13z=±i,±33
Answered by Rasheed.Sindhi last updated on 20/Jan/24
Using k-method  ((z^4 +4z^3 −6z^2 −4z+1)/(z^4 −4z^3 −6z^2 +4z+1))=((z+1)/(z−1))=k (let)  z+1=kz−k  kz−z=k+1  z=((k+1)/(k−1))  ((z^4 +4z^3 −6z^2 −4z+1)/(z^4 −4z^3 −6z^2 +4z+1))=k  z^4 +4z^3 −6z^2 −4z+1−k(z^4 −4z^3 −6z^2 +4z+1)=0  z^4 +4z^3 −6z^2 −4z+1−kz^4 +4kz^3 +6kz^2 −4kz−k=0  (1−k)z^4 +4(1+k)z^3 −6(1−k)z^2 −4(1+k)z+1−k=0  z^4 +4(((1+k)/(1−k)))z^3 −6z^2 −4(((1+k)/(1−k)))z+1=0  z^4 −4(((k+1)/(k−1)))z^3 −6z^2 +4(((k+1)/(k−1)))z+1=0  z^4 −4(z)z^3 −6z^2 +4(z)z+1=0  −3z^3 −2z^2 +1=0  3z^3 +2z^2 −1=0   (z^2 +1)(3z^2 −1)=0  z^2 =−1,(1/3)  z=±i, ±((√3)/3)
Usingkmethodz4+4z36z24z+1z44z36z2+4z+1=z+1z1=k(let)z+1=kzkkzz=k+1z=k+1k1z4+4z36z24z+1z44z36z2+4z+1=kz4+4z36z24z+1k(z44z36z2+4z+1)=0z4+4z36z24z+1kz4+4kz3+6kz24kzk=0(1k)z4+4(1+k)z36(1k)z24(1+k)z+1k=0z4+4(1+k1k)z36z24(1+k1k)z+1=0z44(k+1k1)z36z2+4(k+1k1)z+1=0z44(z)z36z2+4(z)z+1=03z32z2+1=03z3+2z21=0(z2+1)(3z21)=0z2=1,13z=±i,±33
Answered by Rasheed.Sindhi last updated on 29/Jan/24
Componedo-Dividendo version 2  ((z^4 +4z^3 −6z^2 −4z+1)/(z^4 −4z^3 −6z^2 +4z+1))=((z+1)/(z−1))  (((z^4 −6z^2 +1)+(4z^3 −4z))/((z^4 −6z^2 +1)−(4z^3 −4z)))=(((z)+(1))/((z)−(1)))   determinant (((((a+b)/(a−b))=((c+d)/(c−d))⇔(a/b)=(c/d))))  ((z^4 −6z^2 +1)/(4z^3 −4z))=(z/1)  z^4 −6z^2 +1=4z^4 −4z^2   3z^4 +2z^2 −1=0  (z^2 +1)(3z^2 −1)=0   { ((z^2 +1=0 ⇒z∉R)),((3z^2 −1=0⇒z=±(1/( (√3))))) :}
ComponedoDividendoversion2z4+4z36z24z+1z44z36z2+4z+1=z+1z1(z46z2+1)+(4z34z)(z46z2+1)(4z34z)=(z)+(1)(z)(1)a+bab=c+dcdab=cdz46z2+14z34z=z1z46z2+1=4z44z23z4+2z21=0(z2+1)(3z21)=0{z2+1=0zR3z21=0z=±13
Commented by ajfour last updated on 20/Jan/24
Thanks sir. Good ways.
Thankssir.Goodways.

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