Question

Предел (sqrt(x^2+2)-sqrt2)/(sqrt(x^2+1) -1) решить, надо,

Answer 1

$\lim_{x \to 0} \frac{ \sqrt{ x^{2}+2 }- \sqrt{2} }{ \sqrt{ x^{2} +1}-1 }= \lim_{x \to 0} \frac{( \sqrt{ x^{2}+2 }- \sqrt{2})( \sqrt{ x^{2} +1}+1) }{ (\sqrt{ x^{2} +1}-1)( \sqrt{ x^{2} +1}+1) }= \\ \lim_{x \to 0} \frac{( \sqrt{ x^{2}+2 }- \sqrt{2})( \sqrt{ x^{2} +1}+1) }{ x^{2} } = \lim_{x \to 0} \frac{( \sqrt{ x^{2}+2 }- \sqrt{2})( \sqrt{ x^{2} +1}+1)( \sqrt{ x^{2} +2}+ \sqrt{2}) }{ x^{2}( \sqrt{ x^{2} +2}+ \sqrt{2}) }$
$\lim_{x \to 0} \frac{ x^{2} ( \sqrt{ x^{2} +1}+1) }{ x^{2} ( \sqrt{ x^{2} +2}+ \sqrt{2}) }= \lim_{x \to 0} \frac {\sqrt{ x^{2} +1}+1}{\sqrt{ x^{2} +2}+ \sqrt{2}}= \frac{2}{2 \sqrt{2} }= \frac{1}{ \sqrt{2} }$