Answer :
[tex]a<0 \Rightarrow [/tex] the function is increasing in [tex]x\in(-\infty,h][/tex]
[tex]h=-4 \Rightarrow [/tex] the function is increasing in [tex]x\in(-\infty,-4][/tex]
[tex]h=-4 \Rightarrow [/tex] the function is increasing in [tex]x\in(-\infty,-4][/tex]
