![y=\dfrac{e^x(x+4)^4}{\sqrt{5x-1}} y=\dfrac{e^x(x+4)^4}{\sqrt{5x-1}}](https://tex.z-dn.net/?f=y%3D%5Cdfrac%7Be%5Ex%28x%2B4%29%5E4%7D%7B%5Csqrt%7B5x-1%7D%7D)
Прологарифмируем:
![\ln y=\ln\dfrac{e^x(x+4)^4}{\sqrt{5x-1}} \ln y=\ln\dfrac{e^x(x+4)^4}{\sqrt{5x-1}}](https://tex.z-dn.net/?f=%5Cln%20y%3D%5Cln%5Cdfrac%7Be%5Ex%28x%2B4%29%5E4%7D%7B%5Csqrt%7B5x-1%7D%7D)
Правую часть преобразуем пользуясь свойствами логарифма произведения и логарифма частного:
![\ln y=\ln e^x+\ln (x+4)^4-\ln\sqrt{5x-1} \ln y=\ln e^x+\ln (x+4)^4-\ln\sqrt{5x-1}](https://tex.z-dn.net/?f=%5Cln%20y%3D%5Cln%20e%5Ex%2B%5Cln%20%28x%2B4%29%5E4-%5Cln%5Csqrt%7B5x-1%7D)
Упростим:
![\ln y=x+4\ln (x+4)-\dfrac{1}{2} \ln(5x-1) \ln y=x+4\ln (x+4)-\dfrac{1}{2} \ln(5x-1)](https://tex.z-dn.net/?f=%5Cln%20y%3Dx%2B4%5Cln%20%28x%2B4%29-%5Cdfrac%7B1%7D%7B2%7D%20%5Cln%285x-1%29)
Продифференцируем:
![(\ln y)'=\left(x+4\ln (x+4)-\dfrac{1}{2} \ln(5x-1)\right)' (\ln y)'=\left(x+4\ln (x+4)-\dfrac{1}{2} \ln(5x-1)\right)'](https://tex.z-dn.net/?f=%28%5Cln%20y%29%27%3D%5Cleft%28x%2B4%5Cln%20%28x%2B4%29-%5Cdfrac%7B1%7D%7B2%7D%20%5Cln%285x-1%29%5Cright%29%27)
Находим производные, учитывая, в частности, что в левой части стоит производная сложной функции:
![\dfrac{1}{y}\cdot y'=1+4\cdot\dfrac{1}{x+4}\cdot(x+4)'-\dfrac{1}{2} \cdot\dfrac{1}{5x-1} \cdot(5x-1)' \dfrac{1}{y}\cdot y'=1+4\cdot\dfrac{1}{x+4}\cdot(x+4)'-\dfrac{1}{2} \cdot\dfrac{1}{5x-1} \cdot(5x-1)'](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7By%7D%5Ccdot%20y%27%3D1%2B4%5Ccdot%5Cdfrac%7B1%7D%7Bx%2B4%7D%5Ccdot%28x%2B4%29%27-%5Cdfrac%7B1%7D%7B2%7D%20%5Ccdot%5Cdfrac%7B1%7D%7B5x-1%7D%20%5Ccdot%285x-1%29%27)
![\dfrac{1}{y}\cdot y'=1+\dfrac{4}{x+4}\cdot1-\dfrac{1}{2(5x-1)} \cdot5 \dfrac{1}{y}\cdot y'=1+\dfrac{4}{x+4}\cdot1-\dfrac{1}{2(5x-1)} \cdot5](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7By%7D%5Ccdot%20y%27%3D1%2B%5Cdfrac%7B4%7D%7Bx%2B4%7D%5Ccdot1-%5Cdfrac%7B1%7D%7B2%285x-1%29%7D%20%5Ccdot5)
![\dfrac{1}{y}\cdot y'=1+\dfrac{4}{x+4}-\dfrac{5}{2(5x-1)} \dfrac{1}{y}\cdot y'=1+\dfrac{4}{x+4}-\dfrac{5}{2(5x-1)}](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7By%7D%5Ccdot%20y%27%3D1%2B%5Cdfrac%7B4%7D%7Bx%2B4%7D-%5Cdfrac%7B5%7D%7B2%285x-1%29%7D)
Выражаем производную:
![y'=y\left(1+\dfrac{4}{x+4}-\dfrac{5}{2(5x-1)}\right) y'=y\left(1+\dfrac{4}{x+4}-\dfrac{5}{2(5x-1)}\right)](https://tex.z-dn.net/?f=y%27%3Dy%5Cleft%281%2B%5Cdfrac%7B4%7D%7Bx%2B4%7D-%5Cdfrac%7B5%7D%7B2%285x-1%29%7D%5Cright%29)
Подставляем соотношение для y:
![y'=\dfrac{e^x(x+4)^4}{\sqrt{5x-1}}\left(1+\dfrac{4}{x+4}- \dfrac{5}{2(5x-1)}\right) y'=\dfrac{e^x(x+4)^4}{\sqrt{5x-1}}\left(1+\dfrac{4}{x+4}- \dfrac{5}{2(5x-1)}\right)](https://tex.z-dn.net/?f=y%27%3D%5Cdfrac%7Be%5Ex%28x%2B4%29%5E4%7D%7B%5Csqrt%7B5x-1%7D%7D%5Cleft%281%2B%5Cdfrac%7B4%7D%7Bx%2B4%7D-%20%5Cdfrac%7B5%7D%7B2%285x-1%29%7D%5Cright%29)