5. Bi\u1ec3u th\u1ee9c t\u1ecda \u0111\u1ed9 c\u1ee7a t\u00edch v\u00f4 h\u01b0\u1edbng v\u00e0 m\u1ed9t s\u1ed1 \u1ee9ng d\u1ee5ng<\/b><\/p>\n

Trong kh\u00f4ng gian Oxyz , cho hai vect\u01a1:<\/p>\n

<\/p>\n

Ta c\u00f3:<\/p>\n

a) Bi\u1ec3u th\u1ee9c t\u1ecda \u0111\u1ed9 c\u1ee7a t\u00edch v\u00f4 h\u01b0\u1edbng c\u1ee7a hai vect\u01a1\u00a0a\u2192<\/i>,\u00a0b\u2192<\/i>\u00a0l\u00e0<\/p>\n

a\u2192<\/i>.b\u2192<\/i>\u00a0= x.x’ + y.y’ + z.z’<\/p>\n

\u0110\u1eb7c bi\u1ec7t:\u00a0a\u2192<\/i>\u00a0\u22a5\u00a0b\u2192<\/i>\u00a0<=> x.x’ + y.y’ + z.z’ = 0<\/p>\n

b) \u0110\u1ed9 d\u00e0i c\u1ee7a vect\u01a1 :<\/p>\n

<\/p>\n

c) G\u1ecdi \u03c6 l\u00e0 g\u00f3c gi\u1eefa hai vect\u01a1\u00a0a\u2192<\/i>,\u00a0b\u2192<\/i>\u00a0, v\u1edbi\u00a0a\u2192<\/i>\u00a0v\u00e0\u00a0b\u2192<\/i>\u00a0kh\u00e1c\u00a00\u2192<\/i>\u00a0. Khi \u0111\u00f3:<\/p>\n

<\/p>\n

d) Kho\u1ea3ng c\u00e1ch gi\u1eefa hai \u0111i\u1ec3m A(x_{A<\/sub>, yA<\/sub>, zA<\/sub>), B(xB<\/sub>, yB<\/sub>, zB<\/sub>) l\u00e0<\/p>\n}

<\/p>\n

e) N\u1ebfu M l\u00e0 trung \u0111i\u1ec3m c\u1ee7a AB th\u00ec t\u1ecda \u0111\u1ed9 c\u1ee7a M \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1edfi c\u00f4ng th\u1ee9c<\/p>\n

<\/p>\n

f) N\u1ebfu G l\u00e0 tr\u1ecdng t\u00e2m c\u1ee7a tam gi\u00e1c ABC th\u00ec t\u1ecda \u0111\u1ed9 c\u1ee7a G \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1edfi c\u00f4ng th\u1ee9c :<\/p>\n

<\/p>\n

6. Ph\u01b0\u01a1ng tr\u00ecnh m\u1eb7t c\u1ea7u<\/b><\/p>\n

Trong kh\u00f4ng gian Oxyz , ph\u01b0\u01a1ng tr\u00ecnh ch\u00ednh t\u1eafc c\u1ee7a m\u1eb7t c\u1ea7u (S) c\u00f3 t\u00e2m I(a;b;c), b\u00e1n k\u00ednh R l\u00e0: (x – a)^{2<\/sup>\u00a0+ (y – b)2<\/sup>\u00a0+ (z – c)2<\/sup>\u00a0= R2<\/sup>.<\/p>\n}

Ph\u01b0\u01a1ng tr\u00ecnh t\u1ed5ng qu\u00e1t c\u1ee7a m\u1eb7t c\u1ea7u (S) c\u00f3 d\u1ea1ng:<\/p>\n

x^{2<\/sup>\u00a0+ y2<\/sup>\u00a0+ z2<\/sup>\u00a0– 2ax – 2by – 2cz + d = 0<\/p>\n}

V\u1edbi \u0111i\u1ec1u ki\u1ec7n a^{2<\/sup>\u00a0+ b2<\/sup>\u00a0+ c2<\/sup>\u00a0– d2<\/sup>\u00a0. Khi \u0111\u00f3 (S) c\u00f3 t\u00e2m l\u00e0 I(a;b;c) v\u00e0 c\u00f3 b\u00e1n k\u00ednh<\/p>\n}

<\/p>\n","protected":false},"excerpt":{"rendered":"

5. Bi\u1ec3u th\u1ee9c t\u1ecda \u0111\u1ed9 c\u1ee7a t\u00edch v\u00f4 h\u01b0\u1edbng v\u00e0 m\u1ed9t s\u1ed1 \u1ee9ng d\u1ee5ng Trong kh\u00f4ng gian Oxyz , cho hai vect\u01a1: Ta c\u00f3: a) Bi\u1ec3u th\u1ee9c t\u1ecda \u0111\u1ed9 c\u1ee7a t\u00edch v\u00f4 h\u01b0\u1edbng c\u1ee7a hai vect\u01a1\u00a0a\u2192,\u00a0b\u2192\u00a0l\u00e0 a\u2192.b\u2192\u00a0= x.x’ + y.y’ + z.z’ \u0110\u1eb7c bi\u1ec7t:\u00a0a\u2192\u00a0\u22a5\u00a0b\u2192\u00a0<=> x.x’ + y.y’ + z.z’ = 0 b) \u0110\u1ed9 d\u00e0i c\u1ee7a […]<\/p>\n","protected":false},"author":3,"featured_media":28571,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[157],"tags":[1450,1448],"yoast_head":"\n