@[email protected] to Math [email protected]English • 8 months agoWTF 🤦sh.itjust.worksimagemessage-square56fedilinkarrow-up1117arrow-down11
arrow-up1116arrow-down1imageWTF 🤦sh.itjust.works@[email protected] to Math [email protected]English • 8 months agomessage-square56fedilink
minus-square@[email protected]linkfedilinkEnglish3•edit-28 months agoThe square root of x is usually defined as the positive real number that squares to x, so x^2 = 4 => x = ±2 but sqrt(4) = 2, not ±2 The complex sqrt function is multivalued, but that opens a whole other can of worms
minus-squaredigduglinkfedilink6•8 months agoAnd even if you allowed sqrt(4) = ±2, it would still be invalid to evaluate it to -2 on one side of the equation, but then use +2 on the other side.
minus-square@[email protected]OPlinkfedilinkEnglish1•8 months agoOf course, you can only choose one at a time, not mix and match, lol 😂.
minus-square@[email protected]OPlinkfedilinkEnglish2•edit-28 months agoOh yeah, you’re right, now I remembered 🤦. Been a while 😂, almost 20 years.
√4=±2
The square root of x is usually defined as the positive real number that squares to x, so x^2 = 4 => x = ±2 but sqrt(4) = 2, not ±2
The complex sqrt function is multivalued, but that opens a whole other can of worms
And even if you allowed sqrt(4) = ±2, it would still be invalid to evaluate it to -2 on one side of the equation, but then use +2 on the other side.
Of course, you can only choose one at a time, not mix and match, lol 😂.
Oh yeah, you’re right, now I remembered 🤦. Been a while 😂, almost 20 years.