how Richard Feynman would integrate 1/(1+x^2)^2 @blackpenredpen

Uploaded September 2022 | Updated September 2026, 1 week ago

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We can use trig substitution (letting x=tanθ ) to do a typical calculus 2 integral, the integral of 1/(1+x^2)^2. However, we will use Feynman's technique of integration (aka Leibniz's integral rule, aka differentiation under the integral sign) to come up with a very nice integral formula.
Here's the integral of 1/(1+x^2) by using complex numbers 👉 youtu.be/Xhf5iv3adGA

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