can anyone help please...
f = exp(-xy^2)
are they both equal justify your answer
By the chain rule:
By the product rule:
Now carry out the differentiation, remembering to use the product rule again on the 2nd term.
Now do the same again, only change the order of differentiation. Wrt y first, then wrt x. See if you get the same result.
In general if the function is sufficiently smooth.