Cho ham so: y=(2mx^2 +(4m^2 +1)x +32m^3 +2m)/(x+2m).Tim m de ham so co mot diem cuc tri thuoc goc phan tu thu II va mot diem cuc tri thuoc goc phan tu thu IV cua mat phang toa do.
Cho ham so: y=(2mx^2 +(4m^2 +1)x +32m^3 +2m)/(x+2m).Tim m de ham so co mot diem cuc tri thuoc goc phan tu thu II va mot diem cuc tri thuoc goc phan tu thu IV cua mat phang toa do.
dau tien ban phai tinh y'
cho y'=0
de h/s co cuc tri thiy'=0 co 2 nghiem pb
de no nam o goc 1/4 thu 2 thi y>0
nam o goc 1/4 thu 4 thi y<0
su dung "ngoai dong trong khac de xet nghiem nhe"