Definitions Flashcards
(26 cards)
What is the definition of continuity?
What is the statement of sequential continuity?
What is the Intermediate Value Theorem?
What is the statement of existence and continuity for the inverse of a continuous and strictly increasing function f?
What is the statement of boundedness of continuous functions?
Let f: [a, b] -> ℝ be continuous, then f is bounded.
What is the statement of the radius of convergence?
If Σanxn is a power series one of the following three properties hold:
(i) The series only converges if x = 0
(ii) The series converges for all real numbers x
(iii) There is a positive number R with the property that the series converges if |x| < R and diverges if |x| > R
What is the statement of continuity of power series?
Define the exponential function exp(x)
Recall the two inequalities for the exponential referenced in lectures.
- 1 + x =< ex for all real x
- ex =< 1/(1-x) if x < 1
What is the statement of the existence of the logarithm?
There is a continuous strictly increasing function defined on the interval (0, ∞) such that:
(i) elog(x) = x
(ii) log(ey) = y
We have that log(uv) = log(u) + log(v)
What is the definition of powers?
What is the definiton of limits?
If f: I -> R is defined on the open interval I and c ∈ I then f is continuous at c is an equivalent statement to what?
What is the definition of the derivative from first principles?
What are the sum and product rules for derivatives?
What is the chain rule for derivatives?
What is the derivative g’ of a function f: (a, b) -> R with a positive derivative? A function being differentiable with a positive derivative implies its inverse is differentiable.
g = f-1
g’(x) = 1/f’(g(x))
What is the statement of Rolle’s theorem?
Suppose f: [a, b] -> R is continuous on the closed interval [a, b] and differentiable on the open interval (a, b) and that f(a) = f(b), Then there is a point c in the open interval where f’(c) = 0.
What is the statement of the Mean Value Theorem.
Suppose f: [a, b] -> R is continuous on the closed interval [a, b] and differentiable on the open interval (a, b). Then there is a point c ∈ (a, b) where
f’(c) = (f(b) - f(a))/(b - a)
What is the statement of the radius of convergence of Σnanxn-1 ?
Let Σanxn be a power series of radius of convergence R. Then the series Σnanxn-1 has the same radius of convergence.
What is the characteristic property of the exponential?
If x and y are real numbers then exp(x + y) = exp(x) exp(y).
What is the definition of cos(x)?
For x ∈ R:
cos(x) = 1 - x2/2 + x4/24 - … + (-1)k(x2k)/(2k)! + …
What is the definition of sin(x)?
For x ∈ R:
sin(x) = x - x3/6 + x5/120 - … + (-1)k(x2k+1)/(2k+1)! + …
What are the trigonometric addition formulae?
cos(x + y) = cos(x)cos(y) − sin(x)sin(y)
sin(x + y) = sin(x)cos(y) + cos(x)sin(y)