Note 1 to entry: The unit doublet can be used to express the value for x0 of the derivative of a function f(x) differentiable at x= x 0 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaeaaciWaamGadaGadeaabaGaaqaaaOqaaiaadIhacqGH9aqpca WG4bWaaSbaaSqaaKqzadGaaGimaaWcbeaaaaa@3A6D@ :
f ′ ( x 0 )=− ∫ −∞ +∞ δ ′ (x− x 0 ) f(x)dx MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaeaaciWaamGadaGadeaabaGaaqaaaOqaaiqadAgagaqbaiaacI cacaWG4bWaaSbaaSqaaKqzadGaaGimaaWcbeaakiaacMcacqGH9aqp cqGHsisldaWdXaqaaGWaaiqb=r7aKzaafaGaaiikaiaadIhacqGHsi slcaWG4bWaaSbaaSqaaKqzadGaaGimaaWcbeaakiaacMcaaSqaaiaa yIW7cqGHsislcqGHEisPaeaacaaMi8Uaey4kaSIaeyOhIukaniabgU IiYdGccaWGMbGaaiikaiaadIhacaGGPaqcLbqaciGGKbGccaWG4baa aa@547E@