N E U R O

             S T R U C T

             N O T E S

             P O E S I E

             A R G U

             C O L L A B

             M A T H

             P H Y S I Q

Astuces de calcul différentiel



|x|≤(x2+y2)1/2

∣2(x^3)(y^2)/(x^2+y^2)∣≤x^2|y|