Answer:
For ax^2+bx+c=0,
x^2+x(-2-k)+4=0,
So, b=-2-k,
a=1, c=4, so
(-2-k)^2-(4*1*4)>0,
4+4k+k^2-16>0,
k*2+4k-12>0,
(k+6)*(k-2)>0,
the points of interest are
k=-6, k=2, so
look at k<-6, -6<k<2, and
k>2.
Just plug in values for each
interval and you will see
that k<-6 and k>2.
