AP EAMCET202317 May 2023Morning ShiftMathematicsQuadratic EquationActual
If the sum of the cubes of the roots of the equation x^3-a x^2+b x-c=0 is zero, then a^3+3 c=
Options
- A-2 a b
- B2 ab
- C-3 a b
- D3 a b
Correct answer
D. 3 a b
Step-by-step solution
Given: x^3-a x^2+b x-c=0 ...(i) Let , & are the roots equation (i), we get aligned & + + =a & + + =b & =c aligned Also, given: ^3+ ^3+ ^3=0 aligned & ( + + ) ( ^2+ ^2+ ^2- - - )+3 =0 & a (( + + )^2-3( + + ) )+3 c=0 & a [a^2-3 b ]+3 c=0 & a^3-3 a b+3 c=0 a^3+3 c=3 a b aligned