Most Important Selected Qs for JEE AdvancedMathematicsQuadratic Equation
Paragraph: Consider the equation x^4+2 a x^3+x^2+2 a x+1=0 , where a R . Also, range of f(x)=x+ 1 x is (- ,-2] [2, ) Question: If equation has at least two distinct positive real roots, then all possible values of 'a' are
Options
- A(- ,- 1 4 )
- B( 5 4 , )
- C(- ,- 3 4 )
- Dnone of these
Correct answer
A. (- ,- 1 4 )
Step-by-step solution
(x+ 1 x )^2+2 a (x+ 1 x )-1=0 (1) t^2+2 a t-1=0 (2) t 2 and t -2 (Given) Equation (1) will have at least two positive roots, when at least one root of equation (2) will be greater than 2