Calculation interpretation requested

[florida]

Please explain what this is doing?
I understand it is returning a value and that "myIntRate" is dividing a number but the rest with "(1 - (1/Math.pow(1 + .....))))" I dont understand.

Please advise:

return myLoanTot * (myIntRate / (1 - (1/Math.pow(1 + myIntRate,myPayNums))));

[Roy Sinclair]

return myLoanTot * (myIntRate / (1 - (1/Math.pow(1 + myIntRate,myPayNums))));

First 1 is added to myIntRate, the result is then raised to the power of myPayNums, that result is then divided into 1 and the result from that is subtracted from 1, the result from that is divided into myIntRate and that result is then multiplied by myLoanTot and that result is passed back as the end result from the function.