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Calculus1 21 Online
OpenStudy (saitama):

evaluate this integral and ill give medal

OpenStudy (saitama):

\[\int\limits_{}^{}\frac{ (2+\sqrt{x })^2dx }{ \sqrt{x} }\]

OpenStudy (anonymous):

looks like function times its derivative as \[y \prime =\sqrt{x} = \frac{ 1 }{ 2*\sqrt{x} }\]

OpenStudy (anonymous):

\[d(2 + \sqrt{x}) = \frac{ 1 }{ 2 \sqrt{x} } dx\]

OpenStudy (anonymous):

Is it clear?

OpenStudy (saitama):

so \[= (\frac{ 1 }{ 3 })\frac{ (2+\sqrt{x})^3 }{ \sqrt{x} }(\frac{ 1 }{ 2\sqrt{x} })\]

OpenStudy (saitama):

\[\frac{ 1 }{ 6x} *(2+\sqrt{x})^3 \]

OpenStudy (saitama):

@imqwerty

OpenStudy (saitama):

can you help me here my answer is probably wrong,i think

imqwerty (imqwerty):

yeah its wrong you did \(u\) substitution where \(u=2+\sqrt{x}\) right?

OpenStudy (saitama):

so what will happens here?

OpenStudy (saitama):

1/3(2++sqrt of x)^3(1/2sqrtx) ?

OpenStudy (saitama):

1/6sqrtx(2+sqrtx)^3 +c ?

imqwerty (imqwerty):

its not correct :)

imqwerty (imqwerty):

we have this -> \(\color{blueviolet}{u=2+\sqrt{x}}\) now we find the value of \(dx\) \(u=2+\sqrt{x}\) \(\color{blueviolet}{du=\large \frac{1}{2\sqrt{x}} dx}\) when we have this- \(\Large \int \frac{(2+\sqrt{x})^3}{\sqrt{x}}dx\) substituting the purple values we get this- \(\large \int 2u^3 du\) try continuing from here :)

OpenStudy (saitama):

-2(2+sqrtx)^3(1/2qrtx)

OpenStudy (saitama):

-1/sqrtx (2+sqrtx)^3 +c ?

OpenStudy (saitama):

2/3 (u^3) +c ?

OpenStudy (saitama):

opss

OpenStudy (saitama):

2/6sqrtx (u^3)+c

OpenStudy (saitama):

where did you get the 2 in 2u^2du ?

imqwerty (imqwerty):

no this is not correct and i made a lil typo out there it must be this-\(\Large \int \frac{(2+\sqrt{x})^{\color{red}{2}}}{\sqrt{x}}dx\) =\(\large \int 2u^{\color{red}2} du\) and then after we integrate we get this- \(2 \Large \frac{u^{2+1}}{2+1}+c\) sorry the site is lagging a bit for me

imqwerty (imqwerty):

and yeah \(\large \frac{2}{3} u^3 +c\) was correct

imqwerty (imqwerty):

the \(2\) from \(\large\color{blue}{2}u^3 du\) goes here(in blue)-> \(\color{blue}{2}\large \frac{u^{2+1}}{2+1}+c\)

OpenStudy (saitama):

where did you get that 2?

OpenStudy (saitama):

how did you arrive to get that?

imqwerty (imqwerty):

okay we had this-> \[\int\limits_{}^{}2u^3 du\]here that 2 is a constant so we take it out we get this=\[2\int\limits_{}^{}u^3 du\]now we integrate the inner part and get this->\(2 \Large \frac{u^{2+1}}{2+1}+c\)

OpenStudy (saitama):

^^ thanks again

imqwerty (imqwerty):

np :) now just substitute the value of \(u\) to get the final answer

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