what is partial differentiationhow to differentiate ithow to differentiate some complex sums

As with functions of single variablespartial derivatives representthe rates of change of the functions as the variables change. As we saw in the previous section,representsthe rate of change of the function as we change x and hold y fixed whilerepresentsthe rate of change of as we change y and hold x fixed.

for example f(x)=xy
partial diff with respect to x =y because when im diff it partialy take y as constant