Use the Power Rule.

$f(x)$ can be rewritten with a negative exponent.

$f(x)$ can be rewritten with a fractional exponent.

You know that the derivative of $y =\operatorname{sin}x$ is $y'=\operatorname{cos}x$. Well, $f(x)$ is a transformation of $y =\operatorname{sin}x$. So $f'(x)$ (its slope function) will be a transformation of $\operatorname{cos}x$.

The $3$ represents a vertical stretch. How will that transform the derivative (slope) of $y =\operatorname{sin}x$? The $+π$ represents a horizontal shift. How will that transform the derivative (slope) of $y =\operatorname{sin}x$?

The derivative will also be shifted $π$ units to the left and stretched by a factor of $3$.