Q. If the roots $\alpha, \beta$ of the quadratic equation $(\sin 6+\sin 10+\cos 10) x^2+x+k^2-3 k+2=0$, is such that $\alpha<0<\beta$, then the true set of values of $k$ is,
Complex Numbers and Quadratic Equations
Solution:
$\text { Note: } \sin 6+\sin 10+\cos 10<0 $
$\text { So, } f(0)>0 \Rightarrow (k-1)(k-2)>0 $
$\Rightarrow k \in(-\infty, 1) \cup(2, \infty)$
