Parameters estimation.

#1
It is known that a sample consisting of the values 12, 11.2, 13.5, 12.3, 13.8 and 11.9 comes from a population with density functionf (x, α, β) = ( β/ \α ) (1 /x ^{ β +1}), for x>=1, α>0, β>0. Estimate the values of α and β.

Here I have two parameters, and values, do I have to derive first respect to one parameter and the respect to the other? I ask because I think this was what my professor said but we've never done an example with two parameters.

And what will I do with those values? Please guide me in order to start doing this.

Thank you in advance!

Edit: I couldn't find the formula converter, please tell me if you don't understand.