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lim-x-x-2-cot-1-x-4cot-1-x-3x-2-2x-




Question Number 131156 by EDWIN88 last updated on 02/Feb/21
 lim_(x→∞)  ((x^2 cot ((1/x))+4cot ((1/x)))/(3x^2 +2x)) ?
$$\:\underset{{x}\rightarrow\infty} {\mathrm{lim}}\:\frac{{x}^{\mathrm{2}} \mathrm{cot}\:\left(\frac{\mathrm{1}}{{x}}\right)+\mathrm{4cot}\:\left(\frac{\mathrm{1}}{{x}}\right)}{\mathrm{3}{x}^{\mathrm{2}} +\mathrm{2}{x}}\:? \\ $$
Answered by john_santu last updated on 02/Feb/21
 lim_(x→∞)  ((x^2 +4)/(x(3x+2).tan ((1/x)))) =    lim_(x→∞)  ((x^2 +4)/(3x+2)) = lim_(x→∞)  ((1+(4/x^2 ))/((3/x)+(2/x^2 ))) = ∞
$$\:\underset{{x}\rightarrow\infty} {\mathrm{lim}}\:\frac{{x}^{\mathrm{2}} +\mathrm{4}}{{x}\left(\mathrm{3}{x}+\mathrm{2}\right).\mathrm{tan}\:\left(\frac{\mathrm{1}}{{x}}\right)}\:=\: \\ $$$$\:\underset{{x}\rightarrow\infty} {\mathrm{lim}}\:\frac{{x}^{\mathrm{2}} +\mathrm{4}}{\mathrm{3}{x}+\mathrm{2}}\:=\:\underset{{x}\rightarrow\infty} {\mathrm{lim}}\:\frac{\mathrm{1}+\frac{\mathrm{4}}{{x}^{\mathrm{2}} }}{\frac{\mathrm{3}}{{x}}+\frac{\mathrm{2}}{{x}^{\mathrm{2}} }}\:=\:\infty \\ $$