Create a function that will output the three roots of a cubic equation specified by the 4 coefficients listed as input. The output should be sorted using the "sort" function of matlab, to be consistent. Also, the output need only be accurate to the 4th decimal place, and the input "A" will always be non-zero and real.
A*x^3+B*x^2+C*x+D=0 --> [A,B,C,D]
x^3-6x^2+11x-6=0 --> [1,-6,11,-6]
cubicFormula([1,-6,11,-6]) --> [1,2,3]