1
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12
2013
骞翠腑鑰冩暟瀛︽�诲涔犱腑妗ｉ闆嗛敠
1
锛庡鍥撅紝
鈻?/p>
ABC
涓紝
AB=AC
锛?/p>
鈭?/p>
BAC=90
掳
锛?/p>
D
銆?/p>
E
鏄?/p>
BC
涓婄殑涓ょ偣锛屼笖
鈭?/p>
DAE=45
掳
锛庡皢
鈻?/p>
AEC
缁曠潃鐐?/p>
A
椤烘椂閽堟棆杞?/p>
90
掳
鍚庯紝寰楀埌
鈻?/p>
AFB
锛岃繛鎺?/p>
DF
锛?/p>
锛?/p>
1
锛夎鐚滄兂
DF
涓?/p>
DE
涔嬮棿鏈変綍鏁伴噺鍏崇郴锛?/p>
锛?/p>
2
锛夎瘉鏄庝綘鐚滄兂鐨勭粨璁猴紟
2
锛庡鍥撅紝宸茬煡鎶涚墿绾?/p>
y=x
2
+bx+c
缁忚繃
A
锛?/p>
1
锛?/p>
0
锛?/p>
锛?/p>
B
锛?/p>
0
锛?/p>
2
锛変袱鐐癸紝椤剁偣涓?/p>
D
锛庡皢
鈻?/p>
OAB
缁曠偣
A
椤烘椂閽堟棆杞?/p>
90
掳
鍚庯紝鐐?/p>
B
钀藉埌鐐?/p>
C
鐨勪綅缃紝灏嗘姏鐗╃嚎娌?/p>
y
杞村钩绉诲悗缁忚繃鐐?/p>
C
锛屾眰骞崇Щ鍚庢墍寰楀浘
璞＄殑鍑芥暟鍏崇郴寮忥紟
3
锛庡凡鐭ワ細濡傚浘锛?/p>
鈻?/p>
ABC
鍐呮帴浜?/p>
鈯?/p>
O
锛?/p>
AB
涓虹洿寰勶紝寮?/p>
CF
鈯?/p>
AB
浜?/p>
E
锛?/p>
C
鏄?/p>
鐨勪腑鐐癸紝杩炴帴
BD
锛?
杩炴帴
AD
锛屽垎鍒氦
CE
銆?/p>
BC
浜庣偣
P
銆?/p>
Q
锛?/p>
锛?/p>
1
锛夋眰璇侊細
P
鏄?/p>
AQ
鐨勪腑鐐癸紱
锛?/p>
2
锛夎嫢
tan
鈭?/p>
ABC=
锛?/p>
CF=8
锛屾眰
CQ
鐨勯暱锛?/p>
4
锛?/p>
宸茬煡锛?/p>
濡傚浘锛?/p>
鈻?/p>
ABC
涓紝
AB=AC
锛?/p>
浠?/p>
AB
涓虹洿寰勭殑
鈯?/p>
O
浜?/p>
BC
浜庣偣
D
锛岃繃鐐?/p>
D
浣?/p>
DF
鈯?/p>
AC
浜庣偣
F
锛屼氦
BA
鐨勫欢闀跨嚎浜庣偣
E
锛?/p>
姹傝瘉锛?/p>
锛?/p>
1
锛?/p>
BD=CD
锛?/p>
锛?/p>
2
锛?/p>
DE
鏄?/p>
鈯?/p>
O
鐨勫垏绾匡紟