Sorry I don’t understand the question. What do you mean by “Right hand sides will multiply each other”?
I actually was going to include an example of plotting your function initially but then realised I didn’t actually understand what your notation means. If the \binom{x}{y} at the end is supposed to indicate a binomial coefficient, your function might be
∂f(x, y) = √( x^2 + y^2 ) * binomial(x, y)
here I’ve omitted the minus signs in front of x and y, given the numbers are squared anyway).
I suppose that your notation doesn’t actually reference binomial coefficients though given they are only defined for positive integers and you are subtracting decimal numbers in your second equation, which tells me I don’t know what your notation means.
Ranges in Julia can be created with the colon operator. 1:10 will create a range of integers from 1 to 10, while 1:0.1:5 will create the set of numbers 1, 1.1, 1.2, …, 4.9, 5.