二、多選題(每題10分,共20分)
(1)3. 已知圓C:x²+y2=1,下列哪些點向圓C所作兩切線的銳夾角為60°?
(A)(2,0)
(B)(1,3)
(C)(-1,1)
(D)(1,3)
(E) (√√2,-√2)
(2,0)
(A) Y-0 = m(x-2)-
mx-y-2m=0
1 mxo -yxo-2mj
√m²+(-172
(1,3)
(B) y-3=m(x-1)
(-1.1)
(c) Y-1=m(x
mx-y+m-
mx-y+3-m=0
1mxo-yxo+3-ml
1mxo-yxo
1
Jm7+2-412
m=D
m =
(一后,一五)
(E)
(一五一)
香吉試學測複習講義·數學1~2冊-5
m+√3 = 12
Y+ J₂ = mcx+Jz)
x + 5m +5=0
m = ±
(D) (1.53)
塲
Y-√3 = m (X-1)