Sum of 1/n^2+1

Sum of 1/n^2+1 We calculate the famous sum of 1/n^2+1 = 1/(1^2 + 1) + 1/(2^2 + 1) + 1/(3^2 + 1) + ... This is a really nice application of Parseval's formula, which relates the sums of squares of this time the complex Fourier coefficients of f. Applying this to f(x) = e^x gives the sum, which falls out like bread and butter. This is a must-see for anyone who loves partial differential equations or Fourier series. Parseval formula:    • Parseval’s Formula   Complex Fourier Example:    • Complex Fourier Example   Fourier series playlist:    • Fourier Series   Subscribe to my channel:    / drpeyam   Instagram:   / peyamstagram   Teespring merch: https://dr-peyam.creator-spring.com/?