f.4 inequalities唔明ar!!!!!
2007-01-01 2:06 am
有D inequalitie ge問題經常出現 has real roots ,always positive for all real values ofx,has two positive roots,has two unequal negative roots, for real values of x,two unequal real roots ,has no real roots 等字眼,究竟e D字眼有咩意思?仲有冇其他唔同ge字眼?見到e D字眼出現果陣應該discriminant=乜?
回答 (3)
2007-01-01 2:18 am
✔ 最佳答案
has real roots ===> discriminant > 0 or = 0has two positive roots,has two unequal negative roots, two unequal real roots=====> discriminant > 0
no real roots=====> discriminant < 0
其實得3個case
1.有兩個唔同ge roots discriminant就>0
2.得一個root(repeated roots) discriminant就=0
3.冇root discriminant就<0
佢話有roots ge話,即係case1 or 2所以discriminant > or = 0
而always positive for all real values of x係話佢一定大過0
即係冇機會個function係等於0,所以即係冇roots
2007-01-01 2:15 am
有實根， 為全部真正的價值總是確定， 有兩正的根，有兩不相等的負的根，為x，兩不相等的實根的真正的價值，沒有實根
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