/sci/ - Science & Math

>>12158070
Tensor schmensor.
>>12158311
I'm don't think he didn't recognize the equality, he probably actually remembered that [math]\frac{1}{1-x} = \sum_{k = 0}^{\infty} x^k[/math] and [math]\frac{x}{1-x} = \sum_{k = 1}^{\infty} x^k[/math].