To find the first partial derivatives of a function f(x, y), we need to differentiate the function with respect to each variable while treating the other variable as a constant.
Let’s denote the partial derivative with respect to x as fx(x, y) and the partial derivative with respect to y as fy(x, y).
For example, if we have a function like:
- f(x, y) = x^2y + 3xy^2
To find fx(x, y), we treat y as a constant and differentiate with respect to x:
- fx(x, y) = 2xy + 3y^2
Then, to find fy(x, y), we treat x as a constant and differentiate with respect to y:
- fy(x, y) = x^2 + 6xy
Thus, the first partial derivatives are:
- fx(x, y) = 2xy + 3y^2
- fy(x, y) = x^2 + 6xy
This method can be applied to any function of two variables to find the first partial derivatives.