设y=x•ex2,求y′′
设y=x•ex2,求y′′
【正确答案】:y′=x′•ex2+x•(ex2)′ =ex2+2x2•ex2 y′′=(ex2)′+(2x2.ex2)′ =2x•ex2+4xex2+2x2.2xex2 =6xex2+4x3•ex2=2xex2.(3+2x2).
Top