Another stupid question!
Now, I know that we use "h(c-a)(F(c)-F(a)) - h(b-a)((F(b)-F(a))"
But, from what I can tell, that only applys for when there is only one step function. Is someone able to direct me on how to do this/post up the first couple of lines to help me p[lease? As I said, it's the inclusion of that second step function that has me in a twist :(