I have an equation: y^2=4x^2 (My equation is more complicated. This is just an example)
I want to define a function: f(x) = y1 - y2, where y1 and y2 are the roots of the equation in a descending order and then to plot f(x).
I tried to do it as follows:
S := (x) -> sort([solve(y^2 = 4*x^2, y)],`>`)
C := (x) -> S(x)-S(x)
plot(C(x), x = 0 .. 5)
and I had an error "Error, (in S) invalid arguments to sort"
When I remove the `>` option in "sort" it works.
I tried to use "descending" instead of "`>`" as the Maple Help says but I've got another error "Error, (in S) sort: 2nd argument must be a function that always returns true or false"
Can someone help?