Đồ thị hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbb % a9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9 % Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaacaWG5bGaeyypa0 % ZaaSaaaeaacaWG4bGaey4kaSIaaGymaaqaaiaadIhacqGHsislcaaI % Yaaaaaaa!3CD5! y = \frac{{x + 1}}{{x - 2}} (C)\) có các đường tiệm cận là
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Lời giải:
Báo saiTập xác định D = R\{2}
Ta có \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbb % a9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9 % Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaadaWfqaqaaiGacY % gacaGGPbGaaiyBaaWcbaGaamiEaiabgkziUkaaikdadaahaaadbeqa % aiabgUcaRaaaaSqabaGccaWG5bGaeyypa0ZaaCbeaeaaciGGSbGaai % yAaiaac2gaaSqaaiaadIhacqGHsgIRcaaIYaWaaWbaaWqabeaacqGH % RaWkaaaaleqaaOWaaSaaaeaacaWG4bGaey4kaSIaaGymaaqaaiaadI % hacqGHsislcaaIYaaaaiabg2da9iabgUcaRiabg6HiLcaa!4FD6! \mathop {\lim }\limits_{x \to {2^ + }} y = \mathop {\lim }\limits_{x \to {2^ + }} \frac{{x + 1}}{{x - 2}} = + \infty \);\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbb % a9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9 % Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaadaWfqaqaaiGacY % gacaGGPbGaaiyBaaWcbaGaamiEaiabgkziUkaaikdadaahaaadbeqa % aiabgkHiTaaaaSqabaGccaWG5bGaeyypa0ZaaCbeaeaaciGGSbGaai % yAaiaac2gaaSqaaiaadIhacqGHsgIRcaaIYaWaaWbaaWqabeaacqGH % sislaaaaleqaaOWaaSaaaeaacaWG4bGaey4kaSIaaGymaaqaaiaadI % hacqGHsislcaaIYaaaaiabg2da9iabgkHiTiabg6HiLcaa!4FF7! \mathop {\lim }\limits_{x \to {2^ - }} y = \mathop {\lim }\limits_{x \to {2^ - }} \frac{{x + 1}}{{x - 2}} = - \infty \) nên x = 2 là đường tiệm cận đứng của đồ thị hàm số.
Mặt khác \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY-Hhbbf9v8qqaqFr0xc9pk0xbb % a9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9 % Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaadaWfqaqaaiGacY % gacaGGPbGaaiyBaaWcbaGaamiEaiabgkziUkabgglaXkabg6HiLcqa % baGccaWG5bGaeyypa0ZaaCbeaeaaciGGSbGaaiyAaiaac2gaaSqaai % aadIhacqGHsgIRcqGHXcqScqGHEisPaeqaaOWaaSaaaeaacaWG4bGa % ey4kaSIaaGymaaqaaiaadIhacqGHsislcaaIYaaaaiabg2da9iaaig % daaaa!514E! \mathop {\lim }\limits_{x \to \pm \infty } y = \mathop {\lim }\limits_{x \to \pm \infty } \frac{{x + 1}}{{x - 2}} = 1\) nên y =1 là đường tiệm cận ngang của đồ thị hàm số.