2cosa+7sina=0
7sina=-2cosa
7tga=-2
tga=-2/7
49+4=53
sina=-2/sqrt(53)
cosa=7/sqrt(53)
f(min)=(-4-49)/sqrt(53)=-sqrt(53)
2cosa+7sina=0
7sina=-2cosa
7tga=-2
tga=-2/7
49+4=53
sina=-2/sqrt(53)
cosa=7/sqrt(53)
f(min)=(-4-49)/sqrt(53)=-sqrt(53)