If your tabulated x's are in a range named "tabx", one way:


=f(LOOKUP(E12,tabx))

where f() is your function.

In article ,
"Brian Cornejo" wrote:

-- What formula could you enter in cell E13 so that if a value is entered
in cell E12, cell E13 will display the value of f(x) that corresponds to the
largest tabulated x which is less than or equal to the value entered. For
example, if 3 is entered in cell E12, then E13 should display the value of
f(0).
Brian