When to apply negative sign when number is squared

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I always had this confusion of when I need to apply the negative sign in the calculation. I understand that $(-1)^2 = 1$ however why isn't $-1^2 = 1$?

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When we write $-x^2$, it means we square $x$ first, then take the negative of this. That is, $$-x^2 = -\left(x^2\right).$$ So $$-1^2 = -\left(1^2\right)=-1.$$ (And thus $-x^2$ means something different to $(-x)^2$.)

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As it is already in the previous answers:
$(-x)^2\neq-x^2$ To avoid confusion, it is better to use parentheses. $-x^2=-(x^2)$

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Unary minus has lower precedence than elevation to a power.