Why is (n-1)(n+1)=n^2-1?
Last Updated: 29.06.2025 02:50
The more direct answer is to look at a rectangle with sides of n + 1 and n - 1, let’s go with n = 2
Move the nub up to the top:
xxx x
What is the best sunscreen available for summers? My skin is oily.
xx
So, that’s a rectangle with sides 2 and 4.
xxx
Rock Icon, 78, Hauled Off Stage in Jaw-Dropping Concert Farewell - Yahoo
And you are left with almost a square. One less than the square of side n.
xxxx
xxx
What nonsense did you hear today in India that made you laugh?
If you cut off the end of that rectangle, you make it smaller, 2 * 3 and a separate nub of size 1 * 2
xxxx
(n - 1)(n + 1)
The basic answer is that you cross-multiply the values in each factor:
n^2 - n + n - 1
n^2 - 1
xxx x