차별화의 공식은 무엇인가?
To differentiate an implicit function "y"("x"), defined by an equation "R"("x", "y") = 0, it is not generally possible to solve it explicitly for "y" and then differentiate. Instead, one can totally differentiate "R"("x", "y") = 0 with respect to "x" and "y" and then solve the resulting linear equation for "dy" /"dx" to explicitly get the derivative in terms of "x" and "y". Even when it is possible to explicitly solve the original equation, the formula resulting from total differentiation is, in general, much simpler and easier to use.
dy" /"dx