Why is (n-1)(n+1)=n^2-1?
11.06.2025 05:31

(n - 1)(n + 1)
The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2
xxx
Are there any industries or sectors where ChatGPT is particularly well-suited for implementation?
xxx x
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
xxx
Why is it common for guys to sleep with 10-20 women then marry a good girl?
Move the nub up to the top:
n^2 - n + n - 1
n^2 - 1
Why do almost all vertebrates have tails, but not apes and frogs?
xx
And you are left with almost a square. One less than the square of side n.
xxxx
So, that’s a rectangle with sides 2 and 4.
xxx x
xxxx
The basic answer is that you cross-multiply the values in each factor: