Evaluate the indefinite integral.

dx$86$x

Step $1$

We must decide what to choose for u$.$

If

u $=$ f$($x$),$

then

du $=$ f $\text{'}($x$)$ dx$,$

and so it is helpful to look for some expression in

dx$86$x

$=$

$186$x

$$dx

for which the derivative is also present, though perhaps missing a constant factor.

We see that

$86$x

is part of this integral, and the derivative of

$86$x

is $,$ which is simply a constant.