Use definition as a derivative (as a limit) problem

[CrossFit415]

Limit → pi/3 $\frac{2cosθ-1}{3θ-pi}$

I plugged in pi/3 and I got 0/0. I'm not sure that's right way.

Would I need to change the derivative of cosθ to -sinθ? Or just plug pi/3 ?

 

[vela]

Could you state the problem exactly as it's given? I'm not seeing how this is related to the definition of the derivative.