All Flashcards
What is the general form of a logarithmic function?
What is the limit of as x approaches 0 from the right?
What is the limit of as x approaches infinity?
How do you represent a horizontal shift of a logarithmic function?
If , what is the equivalent exponential form?
What is the logarithmic identity for ?
What is the logarithmic identity for ?
What is the change of base formula?
What is the product rule for logarithms?
What is the quotient rule for logarithms?
What is a logarithmic function?
The inverse of an exponential function; 'undoes' exponentiation.
What is the domain of ?
x > 0 (positive real numbers)
What is the range of ?
All real numbers
What is a vertical asymptote?
A vertical line that the graph of a function approaches but never touches.
What is the argument of a logarithm?
The value inside the logarithm, e.g., 'x' in . Must be positive.
What is the base of a logarithm?
The value 'b' in . Determines if the function is increasing or decreasing.
What does concavity mean for a logarithmic function?
Describes the curve's shape: either concave up or concave down, but not both.
What is horizontal shift?
A transformation of a graph where the entire graph is moved left or right.
Define end behavior.
Describes how the function behaves as x approaches positive or negative infinity.
What are transformations of functions?
Changes to a function's graph, such as shifts, stretches, or reflections.
Explain the relationship between logarithmic and exponential functions.
Logarithmic functions are the inverses of exponential functions. They 'undo' each other.
How does the base 'b' affect the graph of ?
If b > 1, the function is increasing. If 0 < b < 1, the function is decreasing.
Why do logarithmic functions have a vertical asymptote at x = 0?
Because the inverse exponential function has a horizontal asymptote at y = 0, restricting the domain of the logarithm to positive values.
Describe the end behavior of a logarithmic function as x approaches infinity.
As x approaches infinity, y also approaches either positive or negative infinity, depending on the base and any transformations.
Explain how horizontal shifts affect the domain and asymptote of a logarithmic function.
A horizontal shift changes the vertical asymptote and, consequently, the domain. For example, shifts the asymptote to x = -k, and the domain becomes x > -k.
Why don't logarithmic functions have maximums, minimums, or inflection points?
Because they are always either increasing or decreasing and always concave up or concave down.
Explain the significance of the domain restriction for logarithmic functions.
The argument of a logarithm must be positive because you cannot raise a base to any power and get a non-positive result.
Describe the effect of a negative sign in front of a logarithmic function.
It reflects the graph across the x-axis, changing increasing functions to decreasing and vice versa, and affecting the end behavior.
How do transformations affect the range of a logarithmic function?
Vertical shifts and stretches can change the range but since the range is all real numbers, only vertical shifts change the graph.
Explain how to determine if a function is logarithmic based on its additive transformations.
If output values are proportional over equal input intervals, then the function is logarithmic.