y = 5 ln ( x ) , y = x ln ( x ) {\displaystyle y=5\ln(x),y=x\ln(x)}
5 ln ( x ) = x ln ( x ) x = 5 x = 1 5 ln ( 2 ) > 2 ln ( 2 ) {\displaystyle {\begin{aligned}5\ln(x)&=x\ln(x)\\[1ex]&x=5\\[1ex]&x=1\\[1ex]5\ln(2)>2\ln(2)\end{aligned}}}
∫ 1 5 ( 5 ln ( x ) − x ln ( x ) ) d x = ∫ 1 5 ( 5 ln ( x ) ) d x − ∫ 1 5 ( x ln ( x ) ) d x = 25 ln ( 5 ) − 20 − ( 25 2 ln ( 5 ) − 6 ) = 25 2 ln ( 5 ) − 14 {\displaystyle \int _{1}^{5}\left(5\ln(x)-x\ln(x)\right)dx={\color {Blue}\int _{1}^{5}\left(5\ln(x)\right)dx}-\int _{1}^{5}\left(x\ln(x)\right)dx=25\ln(5)-20-\left({\frac {25}{2}}\ln(5)-6\right)={\frac {25}{2}}\ln(5)-14}
∫ 1 5 ( 5 ln ( x ) ) d x = 5 ∫ 1 5 ( ln ( x ) ) d x = 5 ( x ln ( x ) | 1 5 − ∫ 1 5 ( x x ) d x ) = 5 ( x ln ( x ) | 1 5 − x | 1 5 ) = 5 ( 5 ln ( 5 ) − 1 ln ( 1 ) − ( 5 − 1 ) ) = 25 ln ( 5 ) − 20 u = ln ( x ) d v = 1 d x d u = 1 x d x v = x {\displaystyle {\begin{aligned}\int _{1}^{5}\left(5\ln(x)\right)dx&=5\int _{1}^{5}\left(\ln(x)\right)dx=5\left(x\ln(x){\bigg |}_{1}^{5}-\int _{1}^{5}\left({\frac {x}{x}}\right)dx\right)=5\left(x\ln(x){\bigg |}_{1}^{5}-x{\bigg |}_{1}^{5}\right)=5\left(5\ln(5)-1\ln(1)-\left(5-1\right)\right)=25\ln(5)-20\\[2ex]u&=\ln(x)\quad dv=1dx\\[2ex]du&={\frac {1}{x}}dx\quad v=x\\[2ex]\end{aligned}}}
∫ 1 5 ( x ln ( x ) ) d x = x 2 ln ( x ) 2 | 1 5 − ∫ 1 5 ( x 2 2 x ) d x = x 2 ln ( x ) 2 | 1 5 − 1 2 ∫ 1 5 ( x ) d x = 1 ln ( 1 ) 2 − 25 ln ( 5 ) 2 − ( 1 2 ) ( x 2 2 ) | 1 5 = 0 − 25 2 ln ( 5 ) − 1 2 ( 25 − 1 2 ) = 25 2 ln ( 5 ) − 6 {\displaystyle \int _{1}^{5}\left(x\ln(x)\right)dx={\frac {x^{2}\ln(x)}{2}}{\bigg |}_{1}^{5}-\int _{1}^{5}\left({\frac {x^{2}}{2x}}\right)dx={\frac {x^{2}\ln(x)}{2}}{\bigg |}_{1}^{5}-{\frac {1}{2}}\int _{1}^{5}\left(x\right)dx={\frac {1\ln(1)}{2}}-{\frac {25\ln(5)}{2}}-\left({\frac {1}{2}}\right)\left({\frac {x^{2}}{2}}\right){\bigg |}_{1}^{5}=0-{\frac {25}{2}}\ln(5)-{\frac {1}{2}}\left({\frac {25-1}{2}}\right)={\frac {25}{2}}\ln(5)-6}
u = ln ( x ) d v = x d x d u = 1 x v = x 2 2 {\displaystyle {\begin{aligned}u&=\ln(x)\quad dv=xdx\\du&={\frac {1}{x}}\quad v={\frac {x^{2}}{2}}\\\end{aligned}}}
![{\displaystyle {\begin{aligned}5\ln(x)&=x\ln(x)\\[1ex]&x=5\\[1ex]&x=1\\[1ex]5\ln(2)>2\ln(2)\end{aligned}}}](https://en.wikipedia.org/api/rest_v1/media/math/render/svg/cd1c3a218d1938f4fbde2e7b79218d92891c3f99)
![{\displaystyle {\begin{aligned}\int _{1}^{5}\left(5\ln(x)\right)dx&=5\int _{1}^{5}\left(\ln(x)\right)dx=5\left(x\ln(x){\bigg |}_{1}^{5}-\int _{1}^{5}\left({\frac {x}{x}}\right)dx\right)=5\left(x\ln(x){\bigg |}_{1}^{5}-x{\bigg |}_{1}^{5}\right)=5\left(5\ln(5)-1\ln(1)-\left(5-1\right)\right)=25\ln(5)-20\\[2ex]u&=\ln(x)\quad dv=1dx\\[2ex]du&={\frac {1}{x}}dx\quad v=x\\[2ex]\end{aligned}}}](https://en.wikipedia.org/api/rest_v1/media/math/render/svg/b15253f63fd4909690663f69175b470d82dea286)
