y-y1=k1(x-x1)
y=k1x-k1x1+y1
y1-k1x1=b
y=k1x+b
- k.
2 M1(x1,y1),
M2(x2,y2) x1¹x2, y1¹y2.
-
12
,
1: y-y1=k(x-x1). .. 2
,
, 2
1: y-y1=k(x-x1) k:
:
:
- - , / 2
/ .
|| ^.
)
S1 {l1,m1} S2 {l2,m2},
p:y=k1x+b1, k1=tgj1
q:y=k2x+b2, k2=tgj2 =>tgj=tg(j2-j1)=
=(tgj2-tgj1)/(1+ tgj1tgj2)=
=(k2-k1)/(1+k1k2).
) p||q, tgj=0, k1=k2
)p^q,
.
1. Ax+By+C=0, M0(x0,y0)
2. - Ax+By+Cz+D=0