Another algebraic identity guaranteed to make you smarter.
2 min readMay 21, 2020
If x can be expressed as (y+z) or (y-z),
Such that y²-z²=1 or y²-z²=(-1),
Then x²+1/x²=2(y²+z²).
Proof:
Case 1: x=(y+z) and y²-z²=1
Case 2: x=(y-z) and y²-z²=1
Case 3: x=(y+z) and y²-z²= (-1)
Case 4: x=(y-z) and y²-z²=(-1)
How to use the identity? Two Examples below
Use them and show how smart you are!!!