Question

Найти производную y=x:5(дробь)+5:x(дробь)

Answer 1

$\frac{x}{5}+ \frac{5}{x}=\frac{ x^{2}+25}{5x} \\ (\frac{ x^{2}+25}{5x})'=\frac{ (x^{2} +25)'5x-(x^{2} +25)(5x)'}{ (5x)^{2} }\\ = \frac{2 x5x-5( x^{2} +25)}{25 x^{2} }= \\ \frac{10 x^{2}-5 x^{2} -125x }{25 x^{2} } = \frac{5 x^{2} -125x}{25 x^{2} }= \\ \frac{5x( x -25)}{25 x^{2} } = \frac{ x-25}{5x}$