Cho số phức z thay đổi thỏa mãn \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaqWaaeaaca % WG6bGaey4kaSIaaGymaiabgkHiTiaadMgaaiaawEa7caGLiWoacqGH % 9aqpcaaIZaaaaa!3F4F! \left| {z + 1 - i} \right| = 3\). Giá trị nhỏ nhất của biểu thức \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyqaiabg2 % da9iaaikdadaabdaqaaiaadQhacqGHsislcaaI0aGaey4kaSIaaGyn % aiaadMgaaiaawEa7caGLiWoacqGHRaWkdaabdaqaaiaadQhacqGHRa % WkcaaIXaGaeyOeI0IaaG4naiaadMgaaiaawEa7caGLiWoaaaa!4A12! A = 2\left| {z - 4 + 5i} \right| + \left| {z + 1 - 7i} \right|\) bằng \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyyamaaka % aabaGaamOyaaWcbeaaaaa!37DB! a\sqrt b \)(với a,b là các số nguyên). Tính S = 2a + b?
A. 20
B. 18
C. 23
D. 17
Lời giải của giáo viên
ToanVN.com
Đặt \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOEaiabg2 % da9iaadIhacqGHRaWkcaWG5bGaamyAaiaaykW7caaMc8+aaeWaaeaa % caWG4bGaaiilaiaadMhacqGHiiIZcqWIDesOaiaawIcacaGLPaaaaa % a!4601! z = x + yi\,\,\left( {x,y \in R} \right)\) nên giả thiết \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyi1HS9aae % WaaeaacaWG4bGaey4kaSIaaGymaaGaayjkaiaawMcaamaaCaaaleqa % baGaaGOmaaaakiabgUcaRmaabmaabaGaamyEaiabgkHiTiaaigdaai % aawIcacaGLPaaadaahaaWcbeqaaiaaikdaaaGccqGH9aqpcaaI5aaa % aa!4532! \Leftrightarrow {\left( {x + 1} \right)^2} + {\left( {y - 1} \right)^2} = 9\).
Do đó \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyqaiabg2 % da9iaaikdadaGcaaqaamaabmaabaGaamiEaiabgkHiTiaaisdaaiaa % wIcacaGLPaaadaahaaWcbeqaaiaaikdaaaGccqGHRaWkdaqadaqaai % aadMhacqGHRaWkcaaI1aaacaGLOaGaayzkaaWaaWbaaSqabeaacaaI % YaaaaaqabaGccqGHRaWkdaGcaaqaamaabmaabaGaamiEaiabgUcaRi % aaigdaaiaawIcacaGLPaaadaahaaWcbeqaaiaaikdaaaGccqGHRaWk % daqadaqaaiaadMhacqGHsislcaaI3aaacaGLOaGaayzkaaWaaWbaaS % qabeaacaaIYaaaaaqabaaaaa!4FB4! A = 2\sqrt {{{\left( {x - 4} \right)}^2} + {{\left( {y + 5} \right)}^2}} + \sqrt {{{\left( {x + 1} \right)}^2} + {{\left( {y - 7} \right)}^2}} \)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0ZaaO % aaaeaadaqadaqaaiaaikdacaWG4bGaeyOeI0IaaGioaaGaayjkaiaa % wMcaamaaCaaaleqabaGaaGOmaaaakiabgUcaRmaabmaabaGaaGOmai % aadMhacqGHRaWkcaaIXaGaaGimaaGaayjkaiaawMcaamaaCaaaleqa % baGaaGOmaaaaaeqaaOGaey4kaSYaaOaaaeaadaqadaqaaiaadIhacq % GHRaWkcaaIXaaacaGLOaGaayzkaaWaaWbaaSqabeaacaaIYaaaaOGa % ey4kaSYaaeWaaeaacaWG5bGaeyOeI0IaaG4naaGaayjkaiaawMcaam % aaCaaaleqabaGaaGOmaaaakiabgUcaRiaaiodadaWadaqaamaabmaa % baGaamiEaiabgUcaRiaaigdaaiaawIcacaGLPaaadaahaaWcbeqaai % aaikdaaaGccqGHRaWkdaqadaqaaiaadMhacqGHsislcaaIXaaacaGL % OaGaayzkaaWaaWbaaSqabeaacaaIYaaaaOGaeyOeI0IaaGyoaaGaay % 5waiaaw2faaaWcbeaaaaa!60D4! = \sqrt {{{\left( {2x - 8} \right)}^2} + {{\left( {2y + 10} \right)}^2}} + \sqrt {{{\left( {x + 1} \right)}^2} + {{\left( {y - 7} \right)}^2} + 3\left[ {{{\left( {x + 1} \right)}^2} + {{\left( {y - 1} \right)}^2} - 9} \right]} \)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0ZaaO % aaaeaadaqadaqaaiaaikdacaWG4bGaeyOeI0IaaGioaaGaayjkaiaa % wMcaamaaCaaaleqabaGaaGOmaaaakiabgUcaRmaabmaabaGaaGOmai % aadMhacqGHRaWkcaaIXaGaaGimaaGaayjkaiaawMcaamaaCaaaleqa % baGaaGOmaaaaaeqaaOGaey4kaSYaaOaaaeaadaqadaqaaiaaikdaca % WG4bGaey4kaSIaaGOmaaGaayjkaiaawMcaamaaCaaaleqabaGaaGOm % aaaakiabgUcaRmaabmaabaGaaGOmaiaadMhacqGHsislcaaI1aaaca % GLOaGaayzkaaWaaWbaaSqabeaacaaIYaaaaaqabaaaaa!51DB! = \sqrt {{{\left( {2x - 8} \right)}^2} + {{\left( {2y + 10} \right)}^2}} + \sqrt {{{\left( {2x + 2} \right)}^2} + {{\left( {2y - 5} \right)}^2}} \)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyyzIm7aaO % aaaeaadaqadaqaaiaaikdacaWG4bGaeyOeI0IaaGioaiabgkHiTiaa % ikdacaWG4bGaeyOeI0IaaGOmaaGaayjkaiaawMcaamaaCaaaleqaba % GaaGOmaaaakiabgUcaRmaabmaabaGaaGOmaiaadMhacqGHRaWkcaaI % XaGaaGimaiabgkHiTiaaikdacaWG5bGaey4kaSIaaGynaaGaayjkai % aawMcaamaaCaaaleqabaGaaGOmaaaaaeqaaOGaeyypa0JaaGynamaa % kaaabaGaaGymaiaaiodaaSqabaGcdaqadaqaamaakaaabaGaamyyam % aaCaaaleqabaGaaGOmaaaakiabgUcaRiaadkgadaahaaWcbeqaaiaa % ikdaaaaabeaakiabgUcaRmaakaaabaGaam4yamaaCaaaleqabaGaaG % OmaaaakiabgUcaRiaadsgadaahaaWcbeqaaiaaikdaaaaabeaakiab % gwMiZoaakaaabaWaaeWaaeaacaWGHbGaey4kaSIaam4yaaGaayjkai % aawMcaamaaCaaaleqabaGaaGOmaaaakiabgUcaRmaabmaabaGaamOy % aiabgUcaRiaadsgaaiaawIcacaGLPaaadaahaaWcbeqaaiaaikdaaa % aabeaaaOGaayjkaiaawMcaaaaa!69E0! \ge \sqrt {{{\left( {2x - 8 - 2x - 2} \right)}^2} + {{\left( {2y + 10 - 2y + 5} \right)}^2}} = 5\sqrt {13} \left( {\sqrt {{a^2} + {b^2}} + \sqrt {{c^2} + {d^2}} \ge \sqrt {{{\left( {a + c} \right)}^2} + {{\left( {b + d} \right)}^2}} } \right)\)
Dấu bằng xảy ra khi và chỉ khi \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca % WG4bGaai4oaiaadMhaaiaawIcacaGLPaaacqGH9aqpdaqadaqaamaa % laaabaGaeyOeI0IaaGinaiabgUcaRiaaigdacaaIYaWaaOaaaeaaca % aIZaaaleqaaaGcbaGaaGymaiaaiodaaaGaai4oamaalaaabaGaaGym % aiaaiMdacqGHsislcaaIXaGaaGioamaakaaabaGaaG4maaWcbeaaaO % qaaiaaigdacaaIZaaaaaGaayjkaiaawMcaaaaa!4A44! \left( {x;y} \right) = \left( {\frac{{ - 4 + 12\sqrt 3 }}{{13}};\frac{{19 - 18\sqrt 3 }}{{13}}} \right)\).
Suy ra \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyqamaaBa % aaleaaciGGTbGaaiyAaiaac6gaaeqaaOGaeyypa0JaaGynamaakaaa % baGaaGymaiaaiodaaSqabaGccqGHshI3caWGHbGaeyypa0JaaGynai % aacUdacaWGIbGaeyypa0JaaGymaiaaiodadaGdKaWcbaaabeGccaGL % sgcacaaIYaGaamyyaiabgUcaRiaadkgacqGH9aqpcaaIYaGaaG4maa % aa!4DD1! {A_{\min }} = 5\sqrt {13} \Rightarrow a = 5;b = 132a + b = 23\)
CÂU HỎI CÙNG CHỦ ĐỀ
Trong không gian Oxyz, cho mặt cầu \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca % WGtbaacaGLOaGaayzkaaGaaiOoamaabmaabaGaamiEaiabgkHiTiaa % igdaaiaawIcacaGLPaaadaahaaWcbeqaaiaaikdaaaGccqGHRaWkda % qadaqaaiaadMhacqGHRaWkcaaIYaaacaGLOaGaayzkaaWaaWbaaSqa % beaacaaIYaaaaOGaey4kaSYaaeWaaeaacaWG6bGaeyOeI0IaaG4maa % GaayjkaiaawMcaamaaCaaaleqabaGaaGOmaaaakiabg2da9iaaikda % caaI3aaaaa!4CB7! \left( S \right):{\left( {x - 1} \right)^2} + {\left( {y + 2} \right)^2} + {\left( {z - 3} \right)^2} = 27\). Gọi \((\alpha)\) là mặt phẳng đi qua hai điểm \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyqamaabm % aabaGaaGimaiaacUdacaaIWaGaai4oaiabgkHiTiaaisdaaiaawIca % caGLPaaacaGGSaGaamOqamaabmaabaGaaGOmaiaacUdacaaIWaGaai % 4oaiaaicdaaiaawIcacaGLPaaaaaa!438D! A\left( {0;0; - 4} \right),B\left( {2;0;0} \right)\) và cắt (S) theo giao tuyến là đường tròn (C). Xét các khối nón có đỉnh là tâm của (S) và đáy là ( C ). Biết rằng khi thể tích của khối nón lớn nhất thì mặt phẳng \((\alpha)\) có phương trình dạng \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyyaiaadI % hacqGHRaWkcaWGIbGaamyEaiabgkHiTiaadQhacqGHRaWkcaWGKbGa % eyypa0JaaGimaaaa!4014! ax + by - z + d = 0\). Tính P = a + b + c.
Trong không gian với hệ trục tọa độ Oxyz, cho hai điểm \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyqamaabm % aabaGaaGOmaiaacUdacaaIXaGaai4oaiaaiodaaiaawIcacaGLPaaa % caGGSaGaamOqamaabmaabaGaaGOnaiaacUdacaaI1aGaai4oaiaaiw % daaiaawIcacaGLPaaaaaa!42B0! A\left( {2;1;3} \right),B\left( {6;5;5} \right)\). Gọi (S) là mặt cầu đường kính AB . Mặt phẳng (P) vuông góc với AB tại H sao cho khối nón đỉnh A và đáy là hình tròn tâm H (giao của mặt cầu (S) và mặt phẳng (P) ) có thể tích lớn nhất, biết rằng \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca % WGqbaacaGLOaGaayzkaaGaaiOoaiaaikdacaWG4bGaey4kaSIaamOy % aiaadMhacqGHRaWkcaWGJbGaamOEaiabgUcaRiaadsgacqGH9aqpca % aIWaaaaa!43E3! \left( P \right):2x + by + cz + d = 0\) với \(b,c,d \in Z\). Tính S = b+c+d.
Cho hình nón có đường cao và đường kính đáy cùng bằng 2a. Cắt hình nón đã cho bởi một mặt phẳng qua trục, diện tích thiết diện bằng
Cho hai số phức \(z_1,z_2\) thỏa mãn \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaqWaaeaaca % WG6bWaaSbaaSqaaiaaigdaaeqaaOGaey4kaSIaaGOmaiabgUcaRiaa % iodacaWGPbaacaGLhWUaayjcSdGaeyypa0JaaGynamaaemaabaGaam % OEamaaBaaaleaacaaIYaaabeaakiabgUcaRiaaikdacqGHRaWkcaaI % ZaGaamyAaaGaay5bSlaawIa7aiabg2da9iaaiodaaaa!4BF6! \left| {{z_1} + 2 + 3i} \right| = 5\left| {{z_2} + 2 + 3i} \right| = 3\). Gọi \(m_0\) là giá trị lớn nhất của phần thực số phức \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca % WG6bWaaSbaaSqaaiaaigdaaeqaaOGaey4kaSIaaGOmaiabgUcaRiaa % iodacaWGPbaabaGaamOEamaaBaaaleaacaaIYaaabeaakiabgUcaRi % aaikdacqGHRaWkcaaIZaGaamyAaaaaaaa!423A! \frac{{{z_1} + 2 + 3i}}{{{z_2} + 2 + 3i}}\). Tìm \(m_0\) .
Cho hàm số bậc bốn \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpcaWG % HbGaamiEamaaCaaaleqabaGaaGinaaaakiabgUcaRiaadkgacaWG4b % WaaWbaaSqabeaacaaIZaaaaOGaey4kaSIaam4yaiaadIhadaahaaWc % beqaaiaaikdaaaGccqGHRaWkcaWGKbGaamiEaiabgUcaRiaadwgaaa % a!4B4E! y = f\left( x \right) = a{x^4} + b{x^3} + c{x^2} + dx + e\) có đồ thị f'(x) như hình vẽ. Phương trình \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm % aabaGaamiEaaGaayjkaiaawMcaaiabg2da9iaaikdacaWGHbGaey4k % aSIaamOyaiabgUcaRiaadogacqGHRaWkcaWGKbGaey4kaSIaamyzaa % aa!4336! f\left( x \right) = 2a + b + c + d + e\) có số nghiệm là
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Trong không gian Oxyz, cho mặt cầu \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca % WGtbaacaGLOaGaayzkaaGaaiOoaiaadIhadaahaaWcbeqaaiaaikda % aaGccqGHRaWkcaWG5bWaaWbaaSqabeaacaaIYaaaaOGaey4kaSIaam % OEamaaCaaaleqabaGaaGOmaaaakiabgkHiTiaaikdacaWG4bGaeyOe % I0IaaGOmaiaadMhacqGHRaWkcaaI2aGaamOEaiabgkHiTiaaigdaca % aIXaGaeyypa0JaaGimaaaa!4CBA! \left( S \right):{x^2} + {y^2} + {z^2} - 2x - 2y + 6z - 11 = 0\). Tọa độ tâm mặt cầu (S) là I(a,b,c). Tính a + b + c.
Trong không gian với hệ tọa độ Oxyz, cho \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyqamaabm % aabaGaamyyaiaacUdacaaIWaGaai4oaiaaicdaaiaawIcacaGLPaaa % caGGSaGaamOqamaabmaabaGaaGimaiaacUdacaWGIbGaai4oaiaaic % daaiaawIcacaGLPaaacaGGSaGaam4qamaabmaabaGaaGimaiaacUda % caaIWaGaai4oaiaadogaaiaawIcacaGLPaaaaaa!49CE! A\left( {a;0;0} \right),B\left( {0;b;0} \right),C\left( {0;0;c} \right)\) và a,b,c dương. Biết rằng khi A,B,C di động trên các tia Ox,Oy,Oz sao cho a+b+c=2018 và khi a,b,c thay đổi thì quỹ tích tâm hình cầu ngoại tiếp tứ diện OABC luôn thuộc mặt phẳng (P) cố định. Tính khoảng cách từ M(1;0;0) tới mặt phẳng (P).
Cho hàm số y =f(x), biết tại các điểm A,B,C đồ thị hàm số có tiếp tuyến được thể hiện trên hình vẽ bên. Mệnh đề nào dưới đây đúng?
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Cho hàm số y = f(x) có đồ thị như hình vẽ. Trong đoạn [-20;20], có bao nhiêu số nguyên m để hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9maaemaabaGaaGymaiaaicdacaWGMbWaaeWaaeaacaWG4bGaeyOe % I0IaamyBaaGaayjkaiaawMcaaiabgkHiTmaalaaabaGaaGymaiaaig % daaeaacaaIZaaaaiaad2gadaahaaWcbeqaaiaaikdaaaGccqGHRaWk % daWcaaqaaiaaiodacaaI3aaabaGaaG4maaaacaWGTbaacaGLhWUaay % jcSdaaaa!4B12! y = \left| {10f\left( {x - m} \right) - \frac{{11}}{3}{m^2} + \frac{{37}}{3}m} \right|\)có 3 điểm cực trị?
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Cho hàm số f(x), đồ thị hàm số f’(x) như hình vẽ.
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Hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4zamaabm % aabaGaamiEaaGaayjkaiaawMcaaiabg2da9iaadAgadaqadaqaaiaa % dIhadaahaaWcbeqaaiaaikdaaaaakiaawIcacaGLPaaacqGHsislda % WcaaqaaiaadIhadaahaaWcbeqaaiaaiAdaaaaakeaacaaIZaaaaiab % gUcaRiaadIhadaahaaWcbeqaaiaaisdaaaGccqGHsislcaWG4bWaaW % baaSqabeaacaaIYaaaaaaa!4824! g\left( x \right) = f\left( {{x^2}} \right) - \frac{{{x^6}}}{3} + {x^4} - {x^2}\) đạt cực tiểu tại bao nhiêu điểm?
Trong các số phức z thỏa mãn \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaqWaaeaada % WcaaqaamaabmaabaGaaGymaiaaikdacqGHsislcaaI1aGaamyAaaGa % ayjkaiaawMcaaiaadQhacqGHRaWkcaaIXaGaaG4naiabgUcaRiaaiE % dacaWGPbaabaGaamOEaiabgkHiTiaaikdacqGHsislcaWGPbaaaaGa % ay5bSlaawIa7aiabg2da9iaaigdacaaIZaaaaa!4BAE! \left| {\frac{{\left( {12 - 5i} \right)z + 17 + 7i}}{{z - 2 - i}}} \right| = 13\). Tìm giá trị nhỏ nhất của |z|.
Gọi \(z_1;z_2\) là các nghiệm phức của phương trình \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOEamaaCa % aaleqabaGaaGOmaaaakiabgkHiTiaaikdacaWG6bGaey4kaSIaaGyn % aiabg2da9iaaicdaaaa!3DEE! {z^2} - 2z + 5 = 0\). Giá trị của biểu thức \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOEamaaDa % aaleaacaaIXaaabaGaaGOmaaaakiabgUcaRiaadQhadaqhaaWcbaGa % aGOmaaqaaiaaikdaaaaaaa!3C26! z_1^2 + z_2^2\) bằng
Cho số phức z thỏa mãn \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOEamaabm % aabaGaaGOmaiabgkHiTiaadMgaaiaawIcacaGLPaaacqGHRaWkcaaI % XaGaaGOmaiaadMgacqGH9aqpcaaIXaaaaa!401A! z\left( {2 - i} \right) + 12i = 1\) . Tính môđun của số phức z.
Biết đồ thị hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg% da9maalaaabaGaamiEaiabgkHiTiaaikdaaeaacaWG4bGaey4kaSIa % aGymaaaaaaa!3D47! y = \frac{{x - 2}}{{x + 1}}\) cắt trục Ox,Oy lần lượt tại hai điểm phân biệt A,B. Tính diện tích của tam giác OAB.
: Trong các số phức z thỏa mãn \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaqWaaeaaca % WG6bWaaWbaaSqabeaacaaIYaaaaOGaey4kaSIaaGymaaGaay5bSlaa % wIa7aiabg2da9iaaikdadaabdaqaaiaadQhaaiaawEa7caGLiWoaaa % a!4287! \left| {{z^2} + 1} \right| = 2\left| z \right|\) gọi \(z_1\) và \(z_2\) lần lượt là các số phức có môđun nhỏ nhất và lớn nhất. Giá trị của biểu thức \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaqWaaeaaca % WG6bWaaSbaaSqaaiaaigdaaeqaaaGccaGLhWUaayjcSdWaaWbaaSqa % beaacaaIYaaaaOGaey4kaSYaaqWaaeaacaWG6bWaaSbaaSqaaiaaik % daaeqaaaGccaGLhWUaayjcSdWaaWbaaSqabeaacaaIYaaaaaaa!42D6! {\left| {{z_1}} \right|^2} + {\left| {{z_2}} \right|^2}\) bằng


