14 ms·
I find it more helpful to note that 1/(1 + x)^2 = 1 - 2x + 3x^2 - 4x^3 + ... for |x| < 1 and then to extend the summation to other values of x.
by spicyj 17y ago
I find it more helpful to note that
1/(1 + x)^2 = 1 - 2x + 3x^2 - 4x^3 + ...
for |x| < 1 and then to extend the summation to other values of x.