I know that you can add functions together, like f(x) = 4x+3 and g(x) = 7x-5 and get a new function, h(x) = 11x-2
Why would someone want to add linear, or quadratic, or whatever functions together? Like are there real world applications for this?
I know you can add the derivatives of the functions together too, and you get h'(x) = 11. In what case would you want to add the derivatives together?