Cоnsider the functiоn $$style{fоnt-size:18pt}{f(x)=x-6sqrt{x}}$$ on the domаin $$style{font-size:18pt}{[0,infty).}$$(а) Find the criticаl points of $$style{font-size:18pt}{f}$$.(b) Find the intervals of increase and decrease of $$style{font-size:18pt}{f}$$.(c) Calculate and classify all local extreme values of $$style{font-size:18pt}{f,}$$ using your answers above.