using Plots
function compute_f_and_df(f,a,b,h)
   x = a:h:b
   y = f.(x)
   dy = (f.(x.+h) .- y)./h
   dy[end] = (y[end] - f(x[end]-h))/h
   return x, y, dy
end

function plot_f_and_df()

    f(x) = exp(2*x)
    x,y,dy = compute_f_and_df(f(x),a,b,h)
    #or
    a = 0
    b = 2pi
    h = 1e-2
    p = compute_f_and_df(g(x),0,2pi,1e-2)
    x,y,dy = plot(x,y,label="f(x)")
    plot!(p,x,dy,label="f'(x)")
    p
    return p
end

plot_f_and_df()

"""
This is how your submission for the exam should look like, you create a function that computes everything you want, and another one that bundles everything.
If your scripts aren't written like that but they are correct it is fine but I am stressing this point so you don't end up fighting more errors.
This is the cleaner and preferred way!
"""