How to find the conditions on the coefficients of a quadratic equation for the roots to be outside the unit circle eg bx^2 + x - 1 = 0 where b is a constant How do we find the condition(s) that b must satisfy such that the roots of the quadratic lie outside the unit circle (ie modulus greater than one)
bx^2 + x - 1 = 0
The Attempt at a Solution
Solve quadratic eqn with the quadratic formulae
We get to -1+/- * sqrt(1+4a) < -2a
This gradually leads to a contradiction.