3 ms·
If sqrt -1 = 0, then (by squaring both sides) -1 = 0, which is clearly unsound.
by munchler 10mo ago
If sqrt -1 = 0, then (by squaring both sides) -1 = 0, which is clearly unsound.
- sebzim4500 10mo agoRight but there isn't a theorem saying `(sqrt x)^2 = x`, there's a theorem saying `x >= 0 -> (sqrt x)^2 = x`
- munchler 10mo agoAh, that makes sense. Thank you. As long as every use of sqrt has such a condition.