Answer:
1/3 sin(3x)+C
Step-by-step explanation:
int (cos(3x) dx)
Let u=3x then du=3 dx so 1/3 du=dx
rewriting integral
int(1/3 cos(u) du)
now evaluating
1/3 sin(u)+C since (sin(u))'=cos(u)
Replace u with 3x
Answer is 1/3 sin(3x)+C
Answer:
Step-by-step explanation:
Integral of cos3x = ⅓sin3x
So when integrating just simply multiply by reciprocal of the cooeffecient of the angle and the integral of that particular trig ratio, in this case it's the sinx.
