exponent

What the excellently named Darth Tickles said.

Or "to the power of", if you missed that day in school too :o)

Or the x^y button on your calculator.



Edit:

So if the full formula is
BrokerFee% = (1% - 0.05% * BrokerRelationsSkill) / 2^(0.14 * FactionStanding + 0.06 * CorporationStanding)

... just start filling in the values one by one. Lets assume your BrokerRelations skill is at level V. So 0.05 * 5 is 0.25. 1 minus 0.25 = 0.75 (incidentally, this is what you'll see on your wallet orders tab listed as "Base Broker Fee).

So now our formula looks like this:
BrokerFee% = 0.75 / 2^(0.14 * FactionStanding + 0.06 * CorporationStanding)

... Lets say your faction standing is 3, so 0.14 * 3 = 0.42. And lets say your corp standing is 6, so 0.06 * 6 = 0.36. We add 0.42 and 0.36 together to get 0.78.

So at this stage the formula is as follows:
BrokerFee% = 0.75 / 2^0.78

... If you can work out 2^0.78 in your head you're a better man than I, so fire up the calculator (scientific mode on the standard Windows one) enter 2, then press the x^y button, the enter 0.78 and your answer should be 1.717.

So now the formula is a simple one:
BrokerFee% = 0.75 / 1.717

... which should be 0.437 when rounded to three decimal places. So dependent upon how the eve client handles rounding your broker fees should amount to 0.44% (or maybe 0.43% if the client trims rather than rounds etc).