Answer:
3/5
Step-by-step explanation:
Firstly we will substitue x = 0 and we will realise that we have 0 in denominator. we will use Lhopitals rule.
[tex]\frac{d}{dx} sin(3x)(cos(3x) = 3cos(6x)\\\frac{d}{dx} 5x = 5\\ \lim_{x \to \infty} \frac{3cos(6*x)}{5} = \frac{3cos(0)}{5} = \frac{3}{5}[/tex]