Manipal MET2010MathematicsQuadratic Equation
If a 1 , roots of the equation (1-a) x^2+3 a x-1=0 are
Options
- Aone positive and one negative
- Bboth negative
- Cboth positive
- Dboth non-real complex
Correct answer
C. both positive
Step-by-step solution
Let , are the roots of the equation (1-a) x^2+3 a x-1=0 , then + = 3 a a-1 , = 1 a-1 As a 1, + 0 and 0 and D=9 a^2+4(1-a)=9 (a^2- 4 9 a+ 4 9 )=9 a (a- 4 9 )+ 4 9 0 , as a 1 The equation has real and positive roots.