Parameters
Func<Double[], Double[]> f
          The function to find roots from.
Double[] initialGuess
          Initial guess of the root.
double accuracy
          Desired accuracy. The root will be refined until the accuracy or the maximum number of iterations is reached. Default 1e-8. Must be greater than 0.
int maxIterations
          Maximum number of iterations. Default 100.
double jacobianStepSize
          Relative step size for calculating the Jacobian matrix at first step. Default 1.0e-4
Return
Double[]
        Returns the root with the specified accuracy.