int x/sqrt(x+1)dx please assist :)
sorry, missed the sqrt part. just a sec.
i think this is a trig substitution and i'm so bad at those lol
try x+1 = u^2
\[\int\limits \frac{ x }{ \sqrt{x+1} }dx=\int\limits x \left( x+1 \right)^{-\frac{ 1 }{ 2 }}\,dx\] you could do integration by parts... have you learned that yet?
yeah, would it be u=(x+1)^(1/2), dv=xdx
no, let u = x
then du = dx and you get rid of the "bad" part. you can integrate 1/(x+1)
you missed the sqrt again lol
sorry, that doesn't prevent it from being integrable, though
ok so do you end up with
u/sqrt(x+1) du
\[\int\limits \frac{ dx }{ \sqrt{x+1} }=\int\limits u^{-\frac{ 1 }{ 2 }}du=2u^{\frac{ 1 }{ 2 }}+c\]
\[=2\sqrt{x+1}\]
+c
but you just lost the xdx and replaced it with just dx how did that happen
|dw:1413132982282:dw|
Join our real-time social learning platform and learn together with your friends!