Hi
I am trying to study partial derivatives but my maths books does not cover it very well-the examples are much too difficult.
I am looking at a previous exam question -can some body tell me if i am on the right track?
Find partial derivatives (df/dx) and (df/dy) -sorry have not worked out how to put proper symbols in yet.
f(x,y)=e^(xy). Cos(y)
i will get the partial derivative when x varies and y is constant first.
Let u=e^(xy) and v=cos(y)
f(x,y)= u. v
Use the product rule.
for the product rule i need du/dx when y is treated as a constant
du/dx=e^(xy).y
I also need dv/dx when x is treated as a constant
dv/dx=0
therefore: the product rule gives df/dx=cos (y^2). e^xy
The is the partial derivative df/dx -i.e when x varies and y is a constant.
Can somebody tell me if this is correct? I will leave the df/dy part until i know my method is correct.
Can recommend a good site that gives easy worked examples that i can follow. Both my maths books do not explain this very well
regards
John