JEE Main 20149 AprilOnline
- Exam
- JEE Main
- Year
- 2014
- Date
- 9 April
- Mode
- Online
- Subject
- Mathematics
- Chapter
- Quadratic Equation
JEE Main 2014 · 9 April · Online · Mathematics · Quadratic Equation
If 1 α , 1 β are the roots of the equation a x ^ 2 + bx + 1 = 0, (a...
If are the roots of the equation , then the equation has roots:
Options
- A and
- B and
- C and
- D and
Correct answer
D. and
Step-by-step solution
a{x}^{2} + bx + 1 = 0\dfrac{1}{\sqrt{\alpha}}, \dfrac{1}{\sqrt{\beta}}⇒ \dfrac{1}{\sqrt{\alpha}} + \dfrac{1}{\sqrt{\beta}} = - \dfrac{b}{a} . . . \left(1\right)\dfrac{1}{\sqrt{\alpha}\sqrt{\beta}} = \dfrac{1}{a} . . . \left(2\right)x\left(x + {b}^{3}\right) + \left({a}^{3} - 3abx\right) = 0⇒ {x}^{2} + \left({b}^{3} - 3ab\right)x + {a}^{3} = 0{a}^{3}⇒ {x}^{2} + {a}^{3}\left\{\left(\dfrac{{b}^{3}}{{a}^{3}}\right) - 3\dfrac{1}{a}\left(\dfrac{b}{a}\right)\right\}x + {a}^{3} = 0,
Roots are .