Question

INTEGRALA DIN ( 3*COS*3X+4X )

Answer 1

$\int\limits {(3cos3x+4sinx)} \, dx = 3\int\limits {cos3x} \, dx + 4\int\limits {sinx} \, dx =\\ =3\cdot \frac{1}{3}\cdot sin3x+4\cdot (-cosx)+C=\\ =sin3x-4cosx+C$