How would you find the arc length of $r(t) = \langle\sqrt{t}, t,t^2\rangle$ for $1\le t\le 4$? This isn't a homework question, I'm just trying to understand how to properly solve a question such as this. I'm working off the textbook Multivariable Calculus by Stewart, and the solutions manual isn't quite explicit on how to do the hardest bits.
I can solve up to the point where: $r'(t) = \sqrt{(1/4t) + 1 + 4t^2}$ but I'm stuck on how to proceed from this point onwards.