Suppose, I wrote an following equation:

> 
> $$f(x)=x^2\tag1$$
> 
> 
> 

NOw I want to refer to it later in my work. Which of the following do I write?

> 
> Using Equation (1) we can see that $f(x)$ is an even function.
> 
> 
> Using equation (1) we can see that $f(x)$ is an even function.
> 
> 
> 

Does referring to a specific equation needs a capital *E* or not?