Question: ```
from math import cos

def diff1(f, x): #approximates first derivative#
 h = 10**(-10)
 return (f(x+h) - f(x))/h

def newtonFunction(f,x):
 return x - f(x)/float(diff1(f,x))

y = cos
x0 = 3
epsilon = .001
print diff1(newtonFunction(y,x0), x0)

```

This is just a portion of the code, but I want to calculate diff1(f,x) where f is newtonFunction but uses the argument f passed to NewtonMinimum. diff1 already takes f and x as an argument and I get an error saying it expects two arguments for newtonFunction.

Answer: 
I assume that Principle is a decimal type in your model. Decimal types are value types and non-nullable, thus .net must always assign a value. If you don't, it assigns the default.

If you don't want the default, you must make the property nullable.
There is One way through `Jquery`. In your model `no need` to make `property nullable`.

Just re-assign the value through `Jquery` if your `Textbox` is having default value.

```
$(document).ready(function () {
   if($('#Principle ').val() == '0.00' || $('#Principle ').val() == '0')
   {
       $('#Principle ').val('');
   }
});

```

This will be triggered when the page is once ready / Completed the loading.

As you know .Net Framework default value will be assigned when if you don't assign the value for the `Value Types`.