3 ms·
> The answer to "Why isn't sqrt(x+y) = sqrt(x) + sqrt(y)" shouldn't be "It's not in the table of 'laws' we're allowed to use". This is the most rigorous and co
by dmurray 9y ago
> The answer to "Why isn't sqrt(x+y) = sqrt(x) + sqrt(y)" shouldn't be "It's not in the table of 'laws' we're allowed to use".
This is the most rigorous and correct answer I can imagine! It's not true because we have not proven it to be true or learnt it from someone who has.
- swiley 9y agoBut it takes a lot of "playing" with math to understand the value in thinking that way. Similarly to how some people start out programming with LOGO or BASIC or bastardized javascript, people who start out in math need some extra help in order be put in the right mental place before they can think about it "correctly."
- posterboy 9y agoBy the same line of reasoning it would be not false until we have proven it false.
- dmurray 9y agoYes, we should consider it neither true nor false, and not use the rule (or its negation) to prove whatever it is we actually want to prove.