is -a squared = (-a) squared

is -a squared = (-a) squared=a^2

-a² is taken to mean -(a²) = -a² by most pieces of technical software because raising to a power takes precedence over negation. 

Not all technical software adopts this convention. Microsoft Excel, for example, takes the opposite view and sets -a² = a²

(which means that it calculates -1² = 1, but also calculates 0-1² = -1)

You should check what convention is adopted by whatever calculator/software you are using.