Asymptotes, Continuity, and Theorems Flashcards
Horizontal Asymptotes
If the limit as x approaches positive or negative infinity of a function equals L, then the line y = L is a horizontal asymptote of the function.
Vertical Asymptotes
The line x = a is a vertical asymptote of the function if either the limit approaching a on the positive or negative side equals positive or negative infinity.
Slant (Oblique) Asymptotes
If the limit of a function over x as x approaches positive or negative infinity equals L, then the line y = Lx is a slant (oblique) asymptote of the function.
A function is continuous as point x = a if
1, f(a) exists. 2, the limit of a function as x approaches a exists. 3, the limit of a function as x approaches a equals f(a). Make sure to check both sides of the limit.
Instantaneous rate of change
The limit as h approaches 0 of average speed, or the derivative at a given point.
IVT
If (f) is a continuous function on a closed interval [a, b] and if ynaught is any value between f(a) and f(b) then ynaught = f(c) for some c in [a, b].
Squeeze Theorem
Suppose that g(x) </= f(x) </= h(x) for all x in some open interval containing c, except possibly at x = c itself. Suppose also that the limit of g(x) as x approaches c = the limit of h(x) as x approaches c = L. Then the limit of f(x) as x approaches c equals L.
MVT
Under certain conditions you can find a point (c) such that its tangent line is parallel to its secant line if f is continuous over [a,b], f is differentiable over (a,b) and there exists at least one real number in (a,b) such that f’(c) = (f(b)-f(a))/(b-a)
Consequences of MVT
- f’(x) = 0 for a<x<b 2. f(x) = C (constant) for a<x<b 3. If f’(x) > 0 (positive) over (a,b) then f(x) is increasing in (a,b). If f’(x) < 0 (negative) over (a,b) then f(x) is decreasing in (a,b).
Rolle’s Theorem
If f is continuous over [a,b], differentiable over (a,b) and f(a) = f(b), then there is at least one number in (a,b) such that f’(c) = 0.
Linearization
L(x) = f’(a)(x-a) +f(a), change in L = f’(a)*change in x
Newton’s Method
Guess first approximation to a solution of the equation f(x) = 0, and then use the formula to find the 1st, 2nd, 3rd approximation and so on. x(n+1) = x(n) - (f(x(n))/f’(x(n))), if f’(x(n)) does not equal 0.
Tangent Line
y - y(0) = m(x - x(0)), where m is the slope (average rate of change, secant line, derivative). Touches the curve at one point.
Secant Line
The average rate of change, or slope. Touches the curve at two points, (x(1), y(1)) and (x(2), y(2)). (y(2) - y(1)/x(2) - x(1)) or [f(x2) - f(x1)]/x2 - x1 = travelled distance/duration = change in y/change in x = rise/run
Normal Line
If the tangent line is y - y(0) = m(x - x(0)), then the normal line is y - y(0) = (-1/m)(x - x(0)), where m is the derivative/slope.