, = xe, . , , = , , > 0, , < 0, ( | | ). = y f, f , , f, = (f). z, = zf, .. , z = , z f = (f).
, , , , f | | | |. f , , , . , < 0 < 0, , e f, = [ ] 蠠 f = [ OF ] (. 1).
e f f e
E O F A F O E A
) )
. 1
> 0 y < 0, = [ ] = [ ] , f = [ F ] , f (. 1).
, .
z, , | z | = | x | | y |, , , . x x 0 = 0 x = 0.
, R , . , .. zx = zy , x = y; , z = 0, x ≠ y, zx = zy = 0. z ≠ 0, zx = zy x = y. , .
x , Î R z, y = xz. : . , R , .
1. ( )
2. :
, x ?
3. + , , , : , = 1,73205..., = 1,41421...
4. .
5