Giới hạn hàm số

H

huynhbachkhoa23

limx2+x29x+20x36x2+11x6=limx2+(x4)(x5)(x1)(x2)(x3)=\lim\limits_{x\to 2^{+}} \dfrac{x^2-9x+20}{x^3-6x^2+11x-6}=\lim\limits_{x\to 2^{+}} \dfrac{(x-4)(x-5)}{(x-1)(x-2)(x-3)}=-∞ do x2>0x-2>0limx2+(x4)(x5)(x1)(x3)=6<0\lim\limits_{x\to 2^{+}}\dfrac{(x-4)(x-5)}{(x-1)(x-3)} =-6<0
limx2x29x+20x36x2+11x6=limx2(x4)(x5)(x1)(x2)(x3)=+\lim\limits_{x\to 2^{-}} \dfrac{x^2-9x+20}{x^3-6x^2+11x-6}=\lim\limits_{x\to 2^{-}} \dfrac{(x-4)(x-5)}{(x-1)(x-2)(x-3)}=+∞ do x2<0x-2<0limx2+(x4)(x5)(x1)(x3)=6<0\lim\limits_{x\to 2^{+}}\dfrac{(x-4)(x-5)}{(x-1)(x-3)} =-6<0
Vậy không tồn tại giới hạn limx2x29x+20x26x2+11x6\lim\limits_{x\to 2}\dfrac{x^2-9x+20}{x^2-6x^2+11x-6}
 
Top Bottom