B\u00e0i 18 (trang 81 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\n

Vi\u1ebft l\u1ea1i bi\u1ec3u th\u1ee9c sau d\u01b0\u1edbi d\u1ea1ng l\u0169y th\u1eeba c\u1ee7a m\u1ed9t s\u1ed1 h\u1eefu t\u1ec9<\/p>\n

<\/p>\n

L\u1eddi gi\u1ea3i:<\/b><\/p>\n

<\/p>\n

<\/p>\n

B\u00e0i 19 (trang 82 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b><\/span><\/p>\n

\u0110\u01a1n gi\u1ea3n bi\u1ec3u th\u1ee9c:<\/p>\n

<\/p>\n

L\u1eddi gi\u1ea3i:<\/b><\/p>\n

<\/p>\n

<\/p>\n

B\u00e0i 20 (trang 82 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\n

T\u00ecm c\u00e1c s\u1ed1 th\u1ee9c \u03b1 th\u00f5a m\u00e3n \u0111i\u1ec1u ki\u1ec7n sau:<\/p>\n

<\/p>\n

L\u1eddi gi\u1ea3i:<\/b><\/p>\n

a) (a^{\u03b1<\/sup>+a(-\u03b1)<\/sup>)\/2=1 <=> a\u03b1<\/sup>+a(-\u03b1)<\/sup>=2 <=> a2\u03b1<\/sup>-2a\u03b1<\/sup>+1=0<\/p>\n}

<=> (a^{\u03b1<\/sup>-1)2<\/sup>=0 <=> a\u03b1<\/sup>-1=0 <=> \u03b1=0<\/p>\n}

b) a^{|\u03b1|<\/sup>\u00a0< 27 <=> 3|\u03b1|<\/sup>\u00a0=33<\/sup>\u00a0<=> |\u03b1|=3 <=> -3 < \u03b1 < 3<\/p>\n}

B\u00e0i 21 (trang 82 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\n

Gi\u1ea3i c\u00e1c b\u1ea5t Ph\u01b0\u01a1ng tr\u00ecnh sau b\u1eb1ng c\u00e1ch \u0111\u1eb7t t=\u221cx<\/p>\n

a) \u221ax+\u221cx=2 \u00a0\u00a0\u00a0 b) \u221ax+3\u221cx+2=0<\/p>\n

L\u1eddi gi\u1ea3i:<\/b><\/p>\n

a) \u0110\u1eb7t t=\u221cx ta \u0111\u01b0\u1ee3c:<\/p>\n

<\/p>\n

V\u1edbi t = 1 => t=\u221cx <=> x = 1<\/p>\n

b) \u0110\u1eb7t t=\u221cx ta \u0111\u01b0\u1ee3c :<\/p>\n

<\/p>\n

V\u1edbi t = 1 <=> x = 1<\/p>\n

V\u1edbi t= 2 <=> x = 8<\/p>\n

B\u00e0i 22 (trang 82 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):<\/b>\u00a0<\/span><\/p>\n

Gi\u1ea3i c\u00e1c Ph\u01b0\u01a1ng tr\u00ecnh sau:<\/p>\n

a) x^{4<\/sup>\u00a0< 3 \u00a0\u00a0\u00a0 b) x11<\/sup>\u00a0\u2265 7 \u00a0\u00a0\u00a0 c) x10<\/sup>\u00a0> 2 \u00a0\u00a0\u00a0 d) x3<\/sup>\u00a0\u2264 5<\/p>\n}

L\u1eddi gi\u1ea3i:<\/b><\/p>\n

a) x^{4<\/sup><3 <=> -\u221c<x<\u221c3<\/p>\n}

<\/p>\n

<\/p>\n

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

B\u00e0i 18 (trang 81 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):\u00a0 Vi\u1ebft l\u1ea1i bi\u1ec3u th\u1ee9c sau d\u01b0\u1edbi d\u1ea1ng l\u0169y th\u1eeba c\u1ee7a m\u1ed9t s\u1ed1 h\u1eefu t\u1ec9 L\u1eddi gi\u1ea3i: B\u00e0i 19 (trang 82 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao): \u0110\u01a1n gi\u1ea3n bi\u1ec3u th\u1ee9c: L\u1eddi gi\u1ea3i: B\u00e0i 20 (trang 82 sgk Gi\u1ea3i T\u00edch 12 n\u00e2ng cao):\u00a0 T\u00ecm c\u00e1c s\u1ed1 […]<\/p>\n","protected":false},"author":3,"featured_media":23533,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[1302],"tags":[1392,1393],"yoast_head":"\n