All Flashcards
What are the differences between horizontal and slant asymptotes?
Horizontal: Function approaches a constant value as x goes to infinity. | Slant: Function approaches a line with a non-zero slope as x goes to infinity.
What are the differences between vertical asymptotes and holes?
Vertical Asymptotes: Occur when the denominator is zero and the factor doesn't cancel. | Holes: Occur when a factor cancels from both numerator and denominator.
Compare and contrast end behavior when numerator degree > denominator degree vs. numerator degree < denominator degree.
Numerator > Denominator: No horizontal asymptote, may have slant asymptote or approaches infinity. | Numerator < Denominator: Horizontal asymptote at y=0.
Compare the end behavior of and .
: Approaches 0 from above and below. | : Approaches 0 from above only.
Compare finding horizontal asymptotes when degrees are equal versus when the denominator's degree is higher.
Degrees equal: Divide leading coefficients. | Denominator higher: Horizontal asymptote is y=0.
What is the difference between polynomial long division and synthetic division for finding slant asymptotes?
Polynomial Long Division: Works for any divisor. | Synthetic Division: Only works for divisors of the form (x - a).
Compare the end behavior of a rational function with a horizontal asymptote at y=2 vs. y=0.
y=2: The function approaches the line y=2 as x approaches infinity. | y=0: The function approaches the x-axis as x approaches infinity.
Compare the graphs of and
: Horizontal asymptote at y=1, vertical asymptote at x=1. | : Horizontal asymptote at y=1, vertical asymptotes at x=1 and x=-1.
Compare the end behavior of rational functions with even vs odd powers in the denominator.
Even powers: Function approaches the horizontal asymptote from the same side for both positive and negative infinity. | Odd powers: Function approaches the horizontal asymptote from opposite sides for positive and negative infinity.
Compare the domain restrictions caused by vertical asymptotes vs. holes.
Vertical asymptotes: Exclude a value from the domain where the function is undefined and approaches infinity. | Holes: Exclude a value from the domain where the function is undefined, but the limit exists.
What does a horizontal asymptote on a rational function's graph indicate?
The value the function approaches as x goes to positive or negative infinity.
What does a vertical asymptote on a rational function's graph indicate?
A point where the function is undefined and approaches infinity or negative infinity.
How can you identify a slant asymptote from a graph?
Look for a line that the function approaches as x goes to positive or negative infinity, but is not horizontal.
How does the graph of behave near x=0?
It approaches positive infinity as x approaches 0 from the right and negative infinity as x approaches 0 from the left.
How does the graph of behave near x=0?
It approaches positive infinity as x approaches 0 from both the left and right.
If a graph of a rational function crosses its horizontal asymptote, what does that mean?
It means the function's value equals the value of the horizontal asymptote at that specific x-value, but it still approaches the asymptote as x goes to infinity.
How to identify a 'hole' on the graph of a rational function.
A hole appears as an open circle on the graph at a specific x-value where the function is undefined but doesn't have a vertical asymptote.
What does the absence of a horizontal asymptote suggest about the rational function's end behavior?
It suggests that the function either approaches infinity or negative infinity, or has a slant asymptote.
How can you use a graph to estimate the limit of a rational function as x approaches infinity?
Observe the y-value that the graph approaches as x moves further and further to the right or left.
What does it mean if a rational function's graph oscillates near a vertical asymptote?
It typically indicates a more complex function or a trigonometric component, rather than a simple rational function.
Formula for a general rational function.
, where P(x) and Q(x) are polynomials.
Horizontal asymptote when degrees are equal.
If , the horizontal asymptote is .
Horizontal asymptote when denominator degree > numerator degree.
If the degree of the denominator is greater, the horizontal asymptote is .
Limit notation for horizontal asymptote at y=b.
How to find a slant asymptote.
Perform polynomial long division. The quotient (without the remainder) is the slant asymptote.
How to find vertical asymptotes.
Solve for in the equation , where is the denominator of the rational function, after simplifying the fraction.
End behavior when numerator degree > denominator degree.
The function tends to or , or has a slant asymptote.
General form of a slant asymptote.
, where and are constants.
How to determine the sign of infinity for end behavior.
Consider the signs of the leading coefficients of the numerator and denominator when is very large (positive or negative).
Express a rational function with factored polynomials.
, where are roots of the numerator and are roots of the denominator.