Question #0f959

1 Answer
Sep 18, 2016

#4/3(x^2+x+1)^(3/2)+C#

Explanation:

We have:

#int(4x+2)(x^2+x+1)^(1/2)dx#

You may not realize it yet, but this is set up quite well for substitution. We will use the substitution #u=x^2+x+1#. Note that this implies that #du=(2x+1)dx#.

Factor a #2# from the #(4x+2)# term:

#=2int(2x+1)(x^2+x+1)^(1/2)dx#

Notice both our #u# and #du# terms are present:

#=2int(x^2+x+1)^(1/2)(2x+1)dx#

#=2intu^(1/2)du#

Using the rule #intu^ndu=u^(n+1)/(n+1)+C#:

#=2(u^(3/2)/(3/2))+C#

#=4/3u^(3/2)+C#

#=4/3(x^2+x+1)^(3/2)+C#