

InterviewSolution
Saved Bookmarks
1. |
If `a`is the root (having the least absolute value) or the equation `x^2-b x-1=0(b in R^+)`, then prove that `-1 |
Answer» Let `f(x) = x^(2) - bx - 1 (b in R^(+))` `f( -1) = b + ve` `f(0) = - 1= - ve` `f(1) = - b = -ve ` Clearly, one root lies in `(-1,0)` and the other in `(1,infty)` . Now , sum of roots is b, which is positive . So .`alpha ` (having the least absolute value) `in (-1, 0)` . |
|