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Showing posts from April 29, 2020

Leibnitz's Rule Statement And It's Proof

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        WELCOME TO MATHEMATICS             I n this mathematics session I shall prove that , under suitable conditions, ' the derivative of the integral and the integral of the derivative are equal ' , and consequently , ' the two repeated integrals are equal for continuous functions '.          Leibnitz's Rule In Mathematics:                If f is defined and continuous on the rectangle R = [a,b;c,d] , and if    (i)  fₓ(x,y) exists and is continuous on the rectangle R , and                      d   (ii) g(x) = ∫ f(x,y) dy , for x∈ [a,b]                     c then g is differentiable on  [a,b] and                            d              g'(x) = ∫ fₓ(x,y) dy                           c                        d                    d i.e.,      d/dx {∫ f(x,y) dy }=∫ ∂f(x,y)/∂x dy                       c                    c  Proof Of Leibnitz's Rule In Mathematics :            Since fₓ (∂f/∂x) exists on R ,