Question

Integrala din cos(3x) =?

Answer 1

Folosim formula:
   
$\int { cos(\alpha x)} \, dx = \frac{sin (\alpha x)}{ \alpha} \\ \\ \text{Rezolvare:} \\ \\ \int{cos(3x)\,} dx = \frac{sin (3 x)}{3}+C$