How can a horizontal axis be curved in a plot? like this

plot(F*r*sin(theta) - m, theta = 0 .. Pi)

how can i sort [x,x/3] to [x/3,x]

sort([x, x/3]) ?

hello. i write a for loop and i want to maple give me the answer like the below pic
thanks in advance

for oo to 2 do
    M[oo] := EI*(4*theta(oo) + 2*theta(oo + 1))/L;
end do;

i want that maple show the value on countor plot like this

with(plots)

contourplot(x*y/486, x = -h/2 .. h/2, y = -a/2 .. a/2, filledregions = true)

i want to find best equation with nonlinear fit or fit for my result
my first variable in column one with name h
 my second variable in column two with name d
 my result in the column 3

i just know that my ratio to b is exponential

Matrix(20, 3, [[70, 8, 8.468140006], [70, 10, 4.105515432], [70, 12, 2.36261199], [70, 14, 1.422093923], [70, 16, 0.9], [100, 8, 20.47249229], [100, 10, 9.618450629], [100, 12, 5.360869165], [100, 14, 3.399312905], [100, 16, 2.640399788], [130, 8, 35.90466304], [130, 10, 17.62958097], [130, 12, 9.828362586], [130, 14, 5.866863694], [130, 16, 3.799262645], [160, 8, 57.31814648], [160, 10, 34.49692774], [160, 12, 15.39340528], [160, 14, 9.991012951], [160, 16, 6.049343013]]);

how can i get best equation with ninlinearFit

thant you so much

i also show my result in below plot