5.5 The Substitution Rule/21

Failed to parse (syntax error): {\displaystyle \int \frac{\cos{(\sqrt{t})}}{\sqrt{t}} dt = 2\int cos u du = \2sinu+c = 2sin(\sqrt{u}) + c }

${\begin{aligned}u&={\sqrt {u}}\\[2ex]du&={\frac {1}{2}}\ {\frac {1}{\sqrt {t}}}dx\\[2ex]2du&={\frac {1}{\sqrt {t}}}dx\end{aligned}}$