Posted by Soroban on September 08, 2002 at 18:49:17:
In Reply to: difference of cubes.. posted by Andrew K on September 08, 2002 at 14:26:08:
: i need to factor using difference of cubes to solve the question (limits) but i dont know how to do it i have (4+3)^3-64 can anyone help i need it ASAP! thanks!
Andrew,
Is your question a simple one?
Are you unfamiliar the difference of cubes formula?
And how come it's "all numbers"?
HA! I just figured it out. Let me know how I do.
You were given f(x) = x^3.
And you were asked to find:
lim [f(x + h) - f(x)]/h, when x = 4.
h->0
And you decided to stick the numbers in first.
If you do that, you might as well grab your
calculator and just do the arithmetic!
Why bother with factoring, algebra, or calculus?
(I don't know where the "3" came from, though.)