Question Number 196107 by maths_plus last updated on 18/Aug/23
$$ \\ $$$$\mathrm{help},\:\mathrm{please}\:! \\ $$$$\underset{{x}\:\rightarrow\:\frac{\boldsymbol{\pi}}{\mathrm{4}}} {{lim}}\:\frac{{cos}\left(\frac{\boldsymbol{\pi}}{\mathrm{4}}\:β{x}\right)β{tan}\:{x}}{\mathrm{1}β{sin}\left(\frac{\boldsymbol{\pi}}{\mathrm{4}}+{x}\right)}\:=\:???\: \\ $$
Answered by MM42 last updated on 21/Aug/23
$${hop}\rightarrow{lim}_{{x}\rightarrow\frac{\pi}{\mathrm{4}}} \:\frac{{sin}\left(\frac{\pi}{\mathrm{4}}β{x}\right)β\left(\mathrm{1}+{tan}^{\mathrm{2}} {x}\right)}{β{cos}\left(\frac{\pi}{\mathrm{4}}+{x}\right)} \\ $$$$=\frac{β\mathrm{2}}{\mathrm{0}}\begin{cases}{{x}\rightarrow\frac{\pi^{+} }{\mathrm{4}}\:\:\:\:\:\:=+\infty}\\{{x}\rightarrow\frac{\pi^{β} }{\mathrm{4}}\:\:\:\:\:\:=β\infty}\end{cases} \\ $$$$\Rightarrow\:{limit}\:\:{not}\:\:{exist} \\ $$$$ \\ $$
Commented by maths_plus last updated on 18/Aug/23
$$\mathrm{thank}\:\mathrm{you} \\ $$