105 a+xb+yc
a=0
=(1, −1, −3)+x(2, 2, 1)+(-1, -1, 0) (1)
x-i
=(2x-y+1, 2x-y-1, x-3)
よって
|
√ a + x b + yc | ²++oe S
=(2x-y+1)²+(2x-y-1)²+(x-3) 2
=(2x − y)²+2(2x− y) +1 A
-
+(2x-y)2-2(2x-y)+1+(x-3)2
これ=2(2x-y)2+(x-3)2 +2
12
ゆえに、a++vc|2は2x-y=0, x-3=0
(S)
数学