2. 如右圖為二次函數y=-2+k的圖
為
形,4為頂點,且交x軸於B、C兩
點,若△ABC為正三角形,則:
(1)k=?
y=x+k (ak)
A
2X = 2x
則 P
C
(2) △ABC面積為多少平方單位?
解:
B
→x
7 (1)
a
22k
k
aa
0=
To= JA AO BO JAB² TO AL AL-AB
= 10 = 50
= (x70)
= √5x² = k
y= Back = 112
2,0)
→x
- lohth = 4-4h+h+
= -
02
(11=6
=
+k
3k+ 6k = 6k-k
=-66
A:(2)1253
6
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