Study Guide #1 S2 Flashcards
What does it mean if y = f(x) is defined at x = a
f(a) exists
An example of a function where y = f(x) is not defined at x = 3
y = 4 / (x - 3)
What are the 3 conditions for a function to be continuous on the interval (a, b)
f(a) is defined (that is, a is in the domain of f)
Lim f(x) as x -> a exists
Lim f(x) as x -> a = f(a)
Write a function that is continuous on the interval (-2, 4)
y = x
What’re the conditions for differentiability
Lim as h -> 0+ = Lim as h -> 0-
What does differentiability imply?
Continuity
What has to be true for Lim f(x) as x -> a to exist?
Lim f(x) as x -> a+ = Lim f(x) as x -> a-
Lim f(x) as x -> a = Infinity
Does the limit exist?
No
Lim f(x) as x -> a+ = 4
Does Lim f(x) as x -> a have to exist?
No, because it may disagree at x = a-
The 2 definitions of a derivative (used for finding derivatives the slow way)
Lim (f(x+h) - f(x)) / h as h -> 0
Lim (f(x) - f(a)) / a as x -> a
Intermediate Value Theorem
Suppose that f is continuous on the closed interval [a, b] and let n be any number between f(a) and f(b) where f(a) can’t equal f(b) then there exists a number c such that f(c) = N
Mean Value Theorem
if f is differentiable on the interval [a, b], then there is a number c between a and b such that:
1. f’(c) = (f(b) - f(a)) / b - a
2. f(b) - f(a) = f’(c)(b - a)
Squeeze Theorem
if f(x) < f(g) < f(h) when x is near a (except possibly at a) and
Lim f(x) as x -> a = Lim h(x) as x -> a = L
then
Lim g(x) as x -> a = L
Interval Method
to find the absolute max and min values on a continuous function f on a closed interval [a, b]
1. find the values of f that are critical numbers on [a, b]
2. find the values of f at the endpoints of the interval
3. the largest value from steps 1 and 2 is the absolute max and the smallest is the absolute min.
Derivative of x^n
nx^n-1