when i input these values it gives me an output of NaN a = 1 b = 2.1 c = 1.010025 any ideas why? i don't even have an output for NaN anywhere forgot to post link to look at it www.thecyberninja.com/quadproject.rar

NaN = not a number, the solution must be imaginary. is that in the form ax^2 + bx + c = 0 [shouldn't be imaginary]?

First off, you learn in math that the numbers CANNOT be decimal/fractions so youd need to unfractionalize em. (Dun know how)

what are you talkling about numbers can not be decimal? double and float make it so you can have decimal places not whole intergers

The first thing you are taught about ax^2 + bx + c = 0 is that A, B, and C have to be integers and no decimal, or fractions. Dont believe me if you wish to do so, but that could be the reason it is coming up with that answer.

they dont have to be ints but can you tell us what happens if you only use ints, well I mean like the types are double or float but your input is whole numbers

a,b,c can be anything you like... but for ease of human calculations it's better to have them as real integers (to get rid of fractions/decimals multiply through by a common denominator/factor) It's just that the discriminate (b^2-4ac) must be >= 0 for it to give a real answer. Else you'll go into imaginary numbers. MdSalih

thats the bit I was lookin in my maths book for you should test the discriminate before performing the calculation to make sure that you arent going to get imaginary numbers

i figured out some of my output problems forgot a ( )to enclude the -b,, it was dividing over just the sqrt then adding or sub the -b gotta work on my float epsilon point now i guess