Hey Paze.
It follows directly from the line above: the only difference in the two lines is that the whole thing is now divided by the delta_x (triangle x) term.
Hi. I'm having a problem why v(x+deltaX) and u(x) become V and U respectively.
The problem is highlighted in my calculations:
http://s7.postimage.org/gqdjxm263/MITprodprood.png
Thanks you very much!
I should probably note that the problem ends as the definition:
And I don't understand how they become V and U in the end.
Bonus question: The teacher keeps saying that for example in the quotient rule proof that v(v+deltaV) becomes v^2 because "they are continuous". I just can't get that part either. Thanks.