sqrt((-1- -3)+(4- -4)^2

I'm thinking you mean:

√(-1 - -3)+(4- -4)^2

We have to start by doing the things in the parentheses, because this comes first in the order of operations.

√(-1 - -3)+(4- -4)^2                ---Remember, subtracting a negative is the same as adding a positive

√(-1 + +3)+(4+ +4)^2

√(-1+3)+(4+4)^2

√(2)+(8)^2                           ---Now we do 8^2, because exponets come next in the order of operations.

√2+64

√66, or about 8.124