Question

Найти производные dy/dx следующих функций

Answer 1

а)

$y = \frac{1}{10 {x}^{5} } - \frac{1}{4 {x}^{4} } = \\ = \frac{1}{10} {x}^{ - 5} - \frac{1}{4} {x}^{ - 4}$

$y' = \frac{1}{10} \times ( - 5) {x}^{ - 6} - \frac{1}{4} \times ( - 4) {x}^{ - 5} = \\ = - \frac{1}{2 {x}^{6} } + \frac{1}{ {x}^{5} }$

б)

$y' = (x)' { \cos}^{2} (3x) + ( { \cos }^{2} (3x))'x = \\ = { \cos}^{2} (3x) + 2 \cos(3x) \times ( - \sin(3x)) \times 3 \times x = \\ = { \cos }^{2} (3x) - 3x \sin(6x)$

в)

$y' = \frac{(1 + ln(x))' x - (x)'(1 + ln(x)) }{ {x}^{2} } = \\ = \frac{ \frac{1}{x} \times x - (1 + ln(x)) }{ {x}^{2} } = \\ = \frac{1 - 1 - ln(x) }{ {x}^{2} } = - \frac{ ln(x) }{ {x}^{2} }$