NDA2015MathematicsQuadratic EquationActual
If the sum of the roots of the equation a x^2+b x+c=0 is equal to the sum of their squares, then
Options
- Aa ^2+ b ^2= c ^2
- Ba^2+b^2=a+b
- Cab + b ^2=2 ac
- Dab - b ^2=2 ac
Correct answer
C. ab + b ^2=2 ac
Step-by-step solution
a x^2+b x+c=0 Let the root be and . aligned & + =- b a , = c a & + = ^2+ ^2 & (given) & + =( + )^2-2 & - b a = (- b a )^2- 2 c a & b^2+a b=2 ac aligned