this post was submitted on 03 Dec 2023
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I don't think you encounter this one very often, but the technically correct
-2^2 = -4has a higher chance of ruining your day.Oh goddammit! Why doesn't PEMDAS prepare us for unary negation??
You mean x^2 =4 where x=±2
No, you'd expect that -2^2 would equal 4, but calculators solve it as -(2)^2 not (-2)^2. But the case you mentioned is also pretty common.
if you've touched polynomials ever, you'd expect the exponent to be before the negation. If you write x³-x² you don't mean x³ + (-x)² = x³+x², you mean x³-(x²)
I think they mean that you said the correct answer is -8 in your first comment. Typo?
I was taught that negative numbers should be written as (-2) with the parentheses when using exponents. So I assume that the calculators are doing it right, or maybe it's just a measure against calculators doing it wrong? I cannot be sure. Also
-2 = 0-2so-2^2 = 0-2^2.No you misunderstand. I'm not talking about the negative. 2² = 4. But in your original comment you said -2² = -8 ? I think you meant -2² = -4
Oh, right. It should have been -4. Thanks.
No big
My calculators have a separate sign button labeled "(–)"
Mine have it too, but it doesn't change the results.