theorems Flashcards
Continuity
Let f be defined at x=c and in an open interval containing x=c
Conditions for continutity
- The limit of f(x) as x approaches c is equal to f(c)
- f(c) needs to be defined
Intermediate Value Theorem
Let f(x) be continuous on [a,b], let g be a number between f(a) and f(b). Then, there is at least one a less than or equal to x and x is less than or equal to b such that f(x)=g
Squeeze Theorem
if f(x)≤g(x)≤h(x) for all numbers, and at some point x=k we have f(k)=h(k), then g(k) must also be equal to them
Existance of Zeroes Corollary
Let f(x) be continuous on [a,b]. Suppose f(a)f(b) ≤ 0, then there exists at least one a≤x≤b such that f(x) = 0
Product Rule Theorem
Let f and g be differentiable functions. Then (fg)’ = f’g+fg’
Quotient Rule Theorem
Let f and g be differentiable functions. (f/g)’ = (f’g-fg’)/g2
Chain Rule Theorem
Assume h(x) and g(x) are differentiable fuctions. Then d/dx(h(g(x))= h’(g(x))g’(x)
General Power Rule Theorem
Assume g(x) is differentiable and a natural number. The, d/dx(g(x)n) = ng(x)n-1 dy/dx
Extreme Value Theorem (EVT)
Assume f(x) is continuous on [a,b]. Then, f attains both its max and min in [a,b].
Local Extrema Definition
- Local min at x=c if f(c) is the minimum value of on some open interval containing c
- local max at x=c f(c) is the maximum value of on some open interval containing c
Critical point definition
c in the domain is called a critical point if either f’(c)=0 or f’(c) does not exist
Fermat’s Theorem for Local Extrema
Assume f(a) is a local max/min. Then x=a is a critical point of f
Extreme Values on a Closed Interval Theorem
Assume f is continuous on [a,b] and f(c) is the min/max. Then x=c is either a critical point or endpoint.
Rolle’s Theorem
Assume f is continuous on [a,b] and differentiable on (a,b) where a=b. Then there exists a point c such that a< c< b and f’(c)=0