NDA2019MathematicsQuadratic EquationActual
If the roots of the equation a(b-c) x^2+b(c-a) x+c(a-b)=0 are equal, then which one of the following is correct?
Options
- Aa, b and c are in AP
- Ba, b and c are in GP
- Ca, b and c are in HP
- Da, b and c do not follow any regular pattern
Correct answer
C. a, b and c are in HP
Step-by-step solution
a(b-c) x^2+b(c-a) x+c(a-b)=0 has coefficients in cyclic order its one root will be 1 . both the roots are equal other root =1 aligned & Product of roots =1 & c(a-b) a(b-c) =1 & a c-b c=a b-a c & 2 a c=a b+b c & 2 b = 1 a + 1 c & a, b, c are in HP. aligned