Question

find f(x+deltax) for f(x) = x^2 -2x-3

Answer 1

whereever you see an x, replace that with \(\large x+\Delta x \)

Answer 2

this is just substitution then simplification

\[f(x + \Delta x) = (x + \Delta x)^2 - 2(x + \Delta x) -2\]

Answer 3

oops -3

Answer 4

do i need to do anything about the delta or is it just part of the variable

Answer 5

well you'll need to expand and then collect like terms...

Answer 6

ok thanks

Answer 7

the delta x just means "a little bit more x". so think of it as just another variable.... most people use "h"...