Evaluate the indefinite integral.

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{cos(\frac{}{x^{28}})}{x^{29}}dx$

tep $1$

$We$ must decide what $to$ choose for $u.$

$Ifu=f(x),$ then $du=f^{\text{'}}(x)dx,$ and $soitis$ helpful $to$ look for some expression for which the derivative $is$ also present, though perhaps missing a constant factor.

$We$ can $re-$write $.$

$We$ see that $\frac{}{x^{28}}is$ part $of$ this integral, and the derivative $of\frac{}{x^{28}}is$