挑战习题
1
/5
单选题
难度:
1.已知一元二次方程:①x
2
+2x+3=0,②x
2
-2x-3=0. 下列说法正确的是()
A
①②都有实数解
B
①无实数解,②有实数解
C
①有实数解,②无实数解
D
①②都无实数解
提示1:
IOeUseS6jui/meS4pOS4quaWueeoi+mDveaYr+S4gOWFg+S6jOasoeaWueeoi++8jOWPr+mAmui/h+axguWHuuKRoOOAgeKRoeeahOWIpOWIq+W8j+eahOaWueW8j+WIpOaWreino+eahOaDheWGteOAgg==
提示2:
IOWFt+S9k+S+neaNru+8muKRoOW9k+KWs++8njDml7bvvIzmlrnnqIvmnInkuKTkuKrkuI3nm7jnrYnnmoTkuKTkuKrlrp7mlbDmoLnvvJvikaHlvZPilrM9MOaXtu+8jOaWueeoi+acieS4pOS4quebuOetieeahOS4pOS4quWunuaVsOague+8m+KRouW9k+KWs++8nDDml7bvvIzmlrnnqIvml6Dlrp7mlbDmoLkuIOWNs+WPr+W+l+WHuuetlOahiC4=
正确答案:
Qg==
PGRpdj7op6PvvJrmlrnnqIvikaDnmoTliKTliKvlvI/ilrM9NC0xMj0tOO+8jOWImeKRoOayoeacieWunuaVsOino++8mzxicj7mlrnnqIvikaHnmoTliKTliKvlvI/ilrM9NCsxMj0yMO+8jOWImeKRoeacieS4pOS4quWunuaVsOinoy4gPGJyPuaVhemAiUIuIDwvZGl2Pg==
2
/5
单选题
难度:
2.
已知函数y=kx+b的图象如图所示,则一元二次方程x
2
+x+k-1=0根的存在情况是( )
A
没有实数根
B
有两个相等的实数根
C
有两个不相等的实数根
D
无法确定
提示1:
PHA+5YWI5qC55o2u5Ye95pWweT1reCti55qE5Zu+6LGh5piv5LiL6ZmN5bm25LiU5Lqk5LqOeei9tOeahOi0n+WNiui9tO+8jOWPr+W+l++8mmvvvJww77yMYu+8nDAuPC9wPg==
提示2:
PHA+5YaN55Sx5LqO6aKY55uu5Lit5omA6KaB5rGC55qE5Yik5pat5LiA5YWD5LqM5qyh5pa556iL5qC55a2Y5Zyo55qE5oOF5Ya177yM5Y+v6YCa6L+H5rGC5Ye65YW25Yik5Yir5byP4paz55qE5pa55byP5Yik5pat6Kej55qE5oOF5Ya144CCPC9wPg==
正确答案:
Qw==
PGRpdj7op6PvvJrmoLnmja7lh73mlbB5PWt4K2LnmoTlm77osaHlj6/lvpfvvJtr77ycMO+8jGLvvJww77yMPGJyPuWImeS4gOWFg+S6jOasoeaWueeoi3g8c3VwPjI8L3N1cD4reCtrLTE9MOS4re+8jOKWsz0xPHN1cD4yPC9zdXA+LTTDlzHDl++8iGstMe+8iT01LTRr77yeMO+8jDxicj7liJnkuIDlhYPkuozmrKHmlrnnqIt4PHN1cD4yPC9zdXA+K3gray0xPTDmoLnnmoTlrZjlnKjmg4XlhrXmmK/mnInkuKTkuKrkuI3nm7jnrYnnmoTlrp7mlbDmoLnvvIw8YnI+5pWF6YCJ77yaQy48L2Rpdj4=
3
/5
单选题
难度:
3.若5k+20<0,则关于x的一元二次方程x
2
+4x-k=0的根的情况是( )
A
没有实数根
B
有两个相等的实数根
C
有两个不相等的实数根
D
无法判断
提示1:
IOagueaNruW3suefpeS4jeetieW8jzVrKzIw77ycMOWPr+axguWHumvnmoTojIPlm7Q=
提示2:
IOWGjeeUseS6jumimOebruS4reaJgOimgeaxgueahOWIpOaWreS4gOWFg+S6jOasoeaWueeoi+agueeahOaDheWGte+8jOWPr+mAmui/h+axguWHuuWFtuWIpOWIq+W8j+KWs+eahOaWueW8j+WIpOaWreino+eahOaDheWGteOAgg==
提示3:
IOWFt+S9k+S+neaNru+8muKRoOW9k+KWs++8njDml7bvvIzmlrnnqIvmnInkuKTkuKrkuI3nm7jnrYnnmoTkuKTkuKrlrp7mlbDmoLnvvJvikaHlvZPilrM9MOaXtu+8jOaWueeoi+acieS4pOS4quebuOetieeahOS4pOS4quWunuaVsOague+8m+KRouW9k+KWs++8nDDml7bvvIzmlrnnqIvml6Dlrp7mlbDmoLkuIOWNs+WPr+W+l+WHuuetlOahiA==
正确答案:
QQ==
PGRpdj7op6PvvJriiLU8aW1nIHdpZHRoPTE2NyBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8yMy80Ny9yQkFDRTFNTVUyX1Q1aXRDQUFBQ3NRWmprNzAwMDAucG5nIj48L2Rpdj48ZGl2PuKItOWvueS6juS4gOWFg+S6jOasoeaWueeoi3g8c3VwPjI8L3N1cD4rNHgtaz0w55qE5Yik5Yir5byP4pazPTE2KzRr77ycMO+8jDxicj7liJnmlrnnqIvmsqHmnInlrp7mlbDmoLkuIDxicj7mlYXpgIlBPC9kaXY+
4
/5
单选题
难度:
4.关于x的一元二次方程(a+1)x
2
-4x-1=0有两个不相等的实数根,则a的取值范围是( )
A
B
C
D
提示1:
IOWcqOS4juS4gOWFg+S6jOasoeaWueeoi+acieWFs+eahOaxguWAvOmXrumimOS4re+8jOaWueeoizxpbWcgd2lkdGg9MTAwIGhlaWdodD0yMSBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzIzLzQ3L3JCQUNFMU1NVTNLaDZqN21BQUFDRzBydXdYODEwNS5wbmciPuiLpeacieS4pOS4quS4jeebuOetieeahOWunuaVsOague+8jOaWueeoi+W/hemhu+a7oei2s+KWsz1iPHN1cD4yPC9zdXA+LTRhY++8njDvvIzlj6/liKnnlKjov5nkuKrmgKfotKjmsYLop6Mu
提示2:
IOS9huS4jeimgeW/veeVpemimOebruS4reaJgOivtOeahOaWueeoi++8iGErMe+8iXg8c3VwPjI8L3N1cD4tNHgtMT0w5Li65LiA5YWD5LqM5qyh5pa556iL5a+55LqM5qyh6aG557O75pWw55qE6ZmQ5Yi25p2h5Lu2
提示3:
IOWImeaciTxpbWcgd2lkdGg9NDMgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMjMvNDcvckJBQ0UxTU1VM0tDYjlodUFBQUJaMjF1aG9VMTkzLnBuZyI+6L+Z5Liq6ZmQ5Yi25p2h5Lu2
正确答案:
Qg==
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
5
/5
单选题
难度:
5.方程
有两个实数根,则k的取值范围是( )
A
B
C
k>1
D
k<1
提示1:
IOmimOebruS4reeahOi/meS4quaWueeoi+iLpeacieS4pOS4quWunuaVsOague+8jOW/hemhu+a7oei2s+KRoOi/meaXtuS4gOS4quS4gOWFg+S6jOasoeaWueeoi+KRoeS4gOWFg+S6jOasoeaWueeoi+WIpOWIq+W8j+KWs+KJpTDov5nkuKTkuKrnibnlvoEu
提示2:
IOagueaNruS4iumdoueahOesrOS4gOS4queJueW+ge+8jOWPr+W+l+WOn+aWueeoi+eahOS6jOasoemhueezu+aVsOS4gOWumuS4jeS4ujDvvIzlj6/lvpcgPGltZyB3aWR0aD0zMyBoZWlnaHQ9MjEgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8wMC81Qi9yQkFDRkZNTVUzWGc3VG4zQUFBQllIRkhVclUyMzAucG5nIj4=
提示3:
IOWGjeagueaNruWOn+aWueeoi+iLpeimgeacieS4pOS4quWunuaVsOagueW/hemhu+KWs+KJpTDvvJvkuKTogIXnu7zlkIjljbPlj6/msYLlvpdr55qE6IyD5Zu0
正确答案:
RA==
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