Question

can't identify what I'm missing: anti-differentiate
4x*(SQRT)x^2 +3 dx

Answer 1

You mean
\[\int\limits 4x \sqrt{x^2+3}dx\]

Answer 2

\[\int\limits_{}^{} 4x \sqrt{x ^{2}+3} dx\]

Answer 3

yup! I've been trying to work it out
and it comes to the end but

Answer 4

Have you tried using u-sub
\[u=x^2+3\]

Answer 5

yes I subbed that in as u, and got \[\frac{ du }{ dx } = 4x\]
the answer is
\[\frac{ 4 }{ 3 }(x ^{2}+3)^{\frac{ 3 }{ 2 }}+c\]

Answer 6

when I work it out after coming to the simplified equation of \[\int\limits_{}^{} \sqrt{u} du\]

Answer 7

Do it like this,
\[u=x^2+3\]
\[du=2xdx\]
\[\frac{du}{2}=xdx\]
------------------------------------------
\[\int\limits\limits 4x \sqrt{x^2+3}dx\]
\[4\int\limits\limits \sqrt{u}\frac{du}{2}\]
\[2 \int\limits \sqrt{u}du\]

Answer 8

You forgot the 2

Answer 9

oh gosh, I just realized I made \[u = x ^{2} +3 = 4x \]
>.<

Answer 10

thank you!
so in questions like this remove the constant outside the integral?

Answer 11

yes

Answer 12

ah alright thank you, do I nee to close this question to ask another question or can I just ask it here?

Answer 13

need*