AP EAMCET202317 May 2023Evening ShiftMathematicsQuadratic EquationActual
If ₁, ₂ and ₃ are the roots of x^3+3 x+2=0 , then ₁^5+ ₂^5+ ₃^5=
Options
- A-30
- B6
- C-6
- D30
Correct answer
D. 30
Step-by-step solution
Since, ₁, ₂ & ₃ are the roots of x^3+3 x+2=0 . aligned & ₁+ ₂+ ₃=0 & ₁ ₂+ ₂ ₃+ ₃ ₁=3 & ₁ ₂ ₃=-2 aligned Now, ₁^5+ ₂^5+ ₃^5= ₁^3 ₁^2+ ₂^3 ₂^2+ ₃^3 ₃^2 aligned & = (-3 ₁-2 ) ₁^2+ (-3 ₂-2 ) ₂^2+ (-3 ₃-2 ) ₃^2 & =-3 ₁^3-2 ₁^2-3 ₂^3-2 ₂^2-3 ₃^3-2 ₃^2 & =- (-3 ₁-2 )-3 (3 ₂-2 )-3 (3 ₃-2 )-2 ( ₁^2+ ₂^2+ ₃^2 ) & =9 ( ₁+ ₂+ ₃ )-2 [ ( ₁+ ₂+ ₃ )^2-2 ( ₂ ₁+ ₂ ₃ . . & =9 0-2 [0^2-2 (3) ]+18 & ₁^5+ ₂^5+ ₃^5=30 aligned