We have:
$$\int t \sec^2(8t) dt$$
Let's use substitution method. Let $u = 8t$, then $\frac{du}{dt} = 8$, and $dt = \frac{1}{8} du$. Also, $t = \frac{u}{8}$. Now, substitute these values into the integral:
$$\int \frac{u}{8} \sec^2(u) \frac{1}{8} du$$
Simplify
Show more…