## jennychan12 Am I doing something wrong? See below. one year ago one year ago

1. jennychan12

$\int\limits (x \sqrt{x+2})dx$

2. jennychan12

u = x+2 ---> x = u-2 so $\int\limits (u-2)u^{\frac{ 1 }{ 2 }} du$ $\int\limits u^{\frac{ 3 }{ 2 }} - 2u^{\frac{ 1 }{ 2 }}$ am i correct so far? if i am i can do the rest

3. jennychan12

oops. forgot the du on the last part

4. jennychan12

If it is it'd be $F(u) = \frac{ 2 }{ 5 } u^{\frac{ 5 }{ 2 }} -\frac{ 4 }{ 3 }u^{\frac{ 3 }{ 2 }}$ and I'd just plug in the u's.

5. shining

true

6. jennychan12

oops forgot the +C I checked the answer and it'd partially correct. i got to the 2/5u..... i don't understand what they did after.

7. slaaibak

they just factorise

8. jennychan12

ohhh ok lemme try that and see if i get it right.. :/

9. precal

at the end they sub u back in

10. jennychan12

-_- that just makes more work oh well i got the answer, thanks.

11. slaaibak

cool