I am planning some posts which will use a few mathematical symbols, but I suspect that some browsers will not be able to read them, and show them as nonsense symbols, blank spaces, or empty rectangles. Please let me know if you cannot read any or all of the following properly. (In each case the symbol itself should be between the double quote marks):

1. "∑" should be large Greek sigma, meaning 'sum of'

2. "σ" should be small Greek sigma, meaning 'standard deviation'

3. "β" should be Greek beta

4. x"²" should be x squared (x with superscript 2)

5. "√"x should be 'square root of x'

6. a"_bc"d should be the letters abcd with the letters bc (and only these) shown as subscripts.