Question

Наайти границы функции lim x направленый к 1 ((sqrt5-+2))/(x^2-4x+3)

Answer 1

$\displaystyle \lim_{x \to1} \frac{ \sqrt{5-x}- \sqrt{2x+2} }{x^2-4x+3} =\displaystyle \lim_{x \to1} \frac{5-x-2x-2}{(x-1)(x-3) (\sqrt{5-x}+ \sqrt{2x+2} ) } =\\ \\ \\ \\ =\displaystyle \lim_{x \to1} \frac{-3x+3}{(x-1)(x-3)( \sqrt{5-x} + \sqrt{2x+2} )} =\\ \\ \\ \\ =\displaystyle \lim_{x \to1} \frac{-3(x-1)}{(x-1)(x-3)( \sqrt{5-x} + \sqrt{2x+2} )} =\\ \\ \\ \\ =\displaystyle \lim_{x \to1} \frac{-3}{(x-3)( \sqrt{5-x} + \sqrt{2x+2} )} = \frac{-3}{(1-3)( \sqrt{5-1} + \sqrt{2\cdot1+2}) } = \frac{3}{8}$