Answer:
Hello,
answer: -2 < k < 8
Step-by-step explanation:
As there are 2 roots: Δ>0
As there is a mininum, k-6 <0 ==> k<6,
minimum :y'=0 ==> (k-6)*2x-8=0 ==> x=4/(k-6)
[tex]\Delta=8^2-4*k*(k-6)\\=64-4k^2+24k\\=-4(k^2-6k+9)+36+64\\=100-4(k-3)^2\\=4(8-k)(k+2)\\\\\Delta\ is\ positive\ for\ -2 < k < 8[/tex]