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lim-x-0-1-x-tan-pi-2-x-




Question Number 131181 by john_santu last updated on 02/Feb/21
 lim_(x→0) ((1/x) − tan ((π/2)−x))=?
$$\:\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\left(\frac{\mathrm{1}}{{x}}\:−\:\mathrm{tan}\:\left(\frac{\pi}{\mathrm{2}}−{x}\right)\right)=? \\ $$
Answered by Ar Brandon last updated on 02/Feb/21
L=lim_(x→0) ((1/x) − tan ((π/2)−x))=lim_(x→0) ((1/x)−cotx)      =lim_(x→0) {((1−xcotx)/x)}=lim_(x→0) {((1−cosx)/x)}=0
$$\mathscr{L}=\underset{\mathrm{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\left(\frac{\mathrm{1}}{{x}}\:−\:\mathrm{tan}\:\left(\frac{\pi}{\mathrm{2}}−{x}\right)\right)=\underset{\mathrm{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\left(\frac{\mathrm{1}}{\mathrm{x}}−\mathrm{cotx}\right) \\ $$$$\:\:\:\:=\underset{\mathrm{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\left\{\frac{\mathrm{1}−\mathrm{xcotx}}{\mathrm{x}}\right\}=\underset{\mathrm{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\left\{\frac{\mathrm{1}−\mathrm{cosx}}{\mathrm{x}}\right\}=\mathrm{0} \\ $$
Answered by john_santu last updated on 02/Feb/21