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Question-30257




Question Number 30257 by mondodotto@gmail.com last updated on 19/Feb/18
Commented by rahul 19 last updated on 19/Feb/18
Sandwhich theorem !
$$\mathrm{Sandwhich}\:\mathrm{theorem}\:! \\ $$
Commented by abdo imad last updated on 21/Feb/18
this question is like why you eat bread...
$${this}\:{question}\:{is}\:{like}\:{why}\:{you}\:{eat}\:{bread}… \\ $$
Commented by rahul 19 last updated on 21/Feb/18
To survive :)
$$\left.\mathrm{To}\:\mathrm{survive}\::\right) \\ $$
Commented by ajfour last updated on 21/Feb/18
Commented by abdo imad last updated on 21/Feb/18
exactly...
$${exactly}… \\ $$
Answered by $@ty@m last updated on 19/Feb/18
We have  sin x=x−(x^3 /(3!))+(x^5 /(5!))−...  ∴lim_(x→0)    ((sin x)/x)  =lim_(x→0) ((x−(x^3 /(3!))+(x^5 /(5!))−...)/x)  =lim_(x→0) ((x(1−(x^2 /(3!))+(x^4 /(4!))−....))/x)  =1−0+0−....  =1
$${We}\:{have} \\ $$$$\mathrm{sin}\:{x}={x}−\frac{{x}^{\mathrm{3}} }{\mathrm{3}!}+\frac{{x}^{\mathrm{5}} }{\mathrm{5}!}−… \\ $$$$\therefore\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\:\:\frac{\mathrm{sin}\:{x}}{{x}} \\ $$$$=\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\frac{{x}−\frac{{x}^{\mathrm{3}} }{\mathrm{3}!}+\frac{{x}^{\mathrm{5}} }{\mathrm{5}!}−…}{{x}} \\ $$$$=\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\frac{{x}\left(\mathrm{1}−\frac{{x}^{\mathrm{2}} }{\mathrm{3}!}+\frac{{x}^{\mathrm{4}} }{\mathrm{4}!}−….\right)}{{x}} \\ $$$$=\mathrm{1}−\mathrm{0}+\mathrm{0}−…. \\ $$$$=\mathrm{1} \\ $$

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