Is there a cleaner syntax for applying an operation to each element of a sequence?

int z = 1;
double result = Math.Log(z);            //works

int[] z = new [] {1,2,3,4};
double[] result = Math.Log(z);            //Syntax 1 - error CS1503: Argument '1': cannot convert from 'int[]' to 'double'
double[] result = z.Select(p => Log(p)).ToArray();  //Syntax 2 - OK

static class LogExtension
  {
    public static IEnumerable<Double> Log(this IEnumerable<int> list)
    {
      foreach (int i in list)
      {
        yield return Math.Log(i);
      }
    }
  }

IEnumerable<Double> logValues = myInts.AsEnumerable().Log();

private static double[] getLogForIntArray(int[] z)
{
    double[] q = (double[])z.Select(p => Math.Log(p)).ToArray();
    return q;
}

double[] q = getLogForIntArray(z); // Syntax 3

int[] z = new [] {1,2,3,4};
double[] result = Array.ConvertAll(z, p => Log(p));

double Log(int i) { return Math.Log(i); }

int[] z = new[] { 1, 2, 3, 4 };
double[] result = Array.ConvertAll(z, Log);

double[] x = Array.ConvertAll(z, p => Math.Log(p));

int[] z = new [] {1,2,3,4};
double[] result = z.Select(p => Log(p)).ToArray();

IEnumerable<int> z = new[] {1, 2, 3, 4};
IEnumerable<double> result = z.Select(i => Math.Log(i));

var z = new[] {1, 2, 3, 4};
var result = z.Select(i => Math.Log(i));

for (int i = 0; i < z.Length; i++)
{
  Math.Log(z[i]);
}

static void Process()
        {
            double[] test = { 1, 2, 3, 4 };
            double[] answer = new double[test.Length];
            for (int i = 0; i < test.Length; i++)
            {
                answer[i] = Math.Log(test[i]);
            }

        }