I know that (-2)^2 = 4 and -2^2 = -4.
However, I do not know what y^2 is when y is a negative number. Is it -y or (-y)?
I'm asking because I got the following question wrong:
a = -2, b = 6
What is a^2 - b?
I substituted the question as follows:
-2^2 - 6 = -10
However the answers was -2, indicating that it should have been substituted like this:
(-2)^2 - 6 = -2;
There were no brackets in the original question. Does that mean that when you substitute a variable with a negative number that it's bracketed by default?
The problem is that $-2^2$ means $-(2\times2)$. $(-2)^2=-2\times-2$. The latter of these $2$ representations is $-2$ squared.