Glossary
Algebraic Manipulation
The process of transforming mathematical expressions using algebraic rules, such as factoring, expanding, or rationalizing, to simplify them or make them easier to evaluate.
Example:
Before finding the limit of as , you would use algebraic manipulation to factor the numerator and cancel the common term.
Composite Function
A function formed by applying one function to the results of another function, often written as $f(g(x))$.
Example:
If and , then is a composite function.
Conjugate
For a binomial expression involving a square root, its conjugate is formed by changing the sign of the second term (e.g., the conjugate of $a - \sqrt{b}$ is $a + \sqrt{b}$).
Example:
To rationalize the denominator of , you would multiply by its conjugate, , on both the numerator and denominator.
Continuous Function
A function whose graph can be drawn without lifting the pen, meaning it has no breaks, jumps, or holes.
Example:
The function is a continuous function because its graph is a smooth, unbroken parabola.
Continuous Function
A function whose graph can be drawn without lifting the pen, meaning it has no breaks, jumps, or holes.
Example:
A polynomial function like is a continuous function for all real numbers, as its graph is a smooth, unbroken curve.
Factorizing
The process of breaking down a polynomial or expression into a product of simpler expressions (factors).
Example:
The expression can be factorized into .
Finite Limit at Infinity
The specific numerical value that a function approaches as its input (x) increases or decreases without bound (tends to positive or negative infinity).
Example:
If , then 7 is the finite limit at infinity, which directly corresponds to a horizontal asymptote at .
Graph
A visual representation of a function's behavior, which can be used to estimate limits and identify asymptotic trends.
Example:
Observing the graph of clearly shows its behavior near and as extends towards positive or negative infinity.
Horizontal Asymptote
A horizontal line that the graph of a function approaches as the input variable increases or decreases without bound, indicating a finite limit at infinity.
Example:
The line y = 3 is a horizontal asymptote for the function , meaning the function's graph flattens out towards y = 3 as x gets very large or very small.
Horizontal Asymptote
A horizontal line that the graph of a function approaches as the input (x) tends towards positive or negative infinity.
Example:
The function has a horizontal asymptote at , indicating that as becomes very large or very small, the function's values get arbitrarily close to 2.
Indeterminate forms
Expressions like $\frac{0}{0}$ or $\frac{\infty}{\infty}$ that arise when evaluating limits by direct substitution, indicating that further analysis or manipulation is required to find the actual limit.
Example:
When trying to find , direct substitution yields the indeterminate form , requiring L'Hopital's Rule or series expansion.
Infinite Limit
An infinite limit occurs when the values of a function become unbounded (either positively or negatively) as the input variable approaches a specific finite value.
Example:
As x approaches 0, the function demonstrates an infinite limit, shooting up towards positive infinity.
Infinite Limits
Limits where the function's value increases or decreases without bound (tends to $\infty$ or $-\infty$) as the input approaches a certain value.
Example:
The function has infinite limits as approaches 0, tending to from the right and from the left.
Infinite Limits of Quotients
Rules for determining the infinite behavior of a quotient of functions when the numerator approaches a non-zero constant and the denominator approaches zero.
Example:
If and , the infinite limits of quotients property helps determine if is or based on the sign of .
Left-hand limit
The value a function approaches as the input variable approaches a specific point from values less than that point.
Example:
When analyzing , the left-hand limit as is -1.
Limit
The value that a function or sequence 'approaches' as the input or index approaches some value. It describes the behavior of a function near a point, rather than at the point itself.
Example:
The limit of as approaches 3 is 6, even though the function is undefined at .
Limit
The value that a function approaches as its input approaches some specific value.
Example:
For the function , the limit as approaches 3 is 5, meaning the function's output gets arbitrarily close to 5 as the input gets close to 3.
Limit
The value that a function approaches as its input approaches a certain point, without necessarily reaching that value.
Example:
For the function , the limit as x approaches 3 is 9, meaning as x gets infinitesimally close to 3, gets arbitrarily close to 9.
Limit at Infinity
A limit at infinity describes the long-term behavior of a function, specifically what value the function's output approaches as its input variable increases or decreases without bound.
Example:
For the function , the limit at infinity as x approaches positive infinity is 2, showing the function stabilizes at that value.
Limit at infinity
The value a function approaches as its input variable grows infinitely large (positive or negative).
Example:
For , the limit at infinity as is 0, indicating the function approaches the x-axis.
Limit of 1/x^n as x Approaches 0
Describes how the function $1/x^n$ behaves as x approaches 0 from the positive or negative side, resulting in positive or negative infinity depending on 'n' being even or odd.
Example:
When analyzing the behavior of near , the limit of 1/x^n as x approaches 0 tells us it tends to from both sides because is even.
Limit of a Composite Function
If the outer function is continuous at the limit of the inner function, the limit of a composite function can be found by evaluating the outer function at the limit of the inner function.
Example:
For , since is continuous, you can find and then evaluate , applying the limit of a composite function.
Limit of a Constant Function
The limit of a constant function as the input approaches any value 'a' is always the constant itself.
Example:
If you're calculating the speed of light, which is a constant, its limit of a constant function as time approaches any point is still the speed of light.
Limit of a Multiple of a Function
The limit of a constant multiplied by a function is the constant multiplied by the limit of the function.
Example:
If , then uses the limit of a multiple of a function to become .
Limit of a Product of Functions
The limit of the product of two functions is the product of their individual limits, assuming both limits exist.
Example:
When evaluating , you can use the limit of a product of functions to multiply by .
Limit of a Quotient of Functions
The limit of a quotient of two functions is the quotient of their individual limits, provided the limit of the denominator is not zero.
Example:
To find , you apply the limit of a quotient of functions, calculating the limit of the numerator and denominator separately.
Limit of a Sum or Difference of Functions
The limit of a sum or difference of functions is the sum or difference of their individual limits, provided those limits exist.
Example:
To find , you can apply the limit of a sum or difference of functions to evaluate and separately.
Limit of the Power of a Function
The limit of a function raised to a power is the limit of the function raised to that same power, for any real number power.
Example:
If you need to find , you can first find and then square the result, using the limit of the power of a function.
Limit properties
Rules that allow algebraic manipulation of limits to simplify complex functions and determine their behavior.
Example:
Using limit properties, we can break down into simpler parts like and .
Limits
The value that a function approaches as its input values get arbitrarily close to a certain point. They are fundamental to calculus, defining derivatives and integrals.
Example:
When analyzing the function , the limit as x approaches 0 is 1, even though the function itself is undefined at x=0.
Nonexistent Limits
A situation where a function does not approach a single, finite value as its input approaches a certain point. This can occur if the function is unbounded, oscillates, or has unequal one-sided limits.
Example:
The function has a nonexistent limit as x approaches because the function becomes unbounded.
One-Sided Limit
The value a function approaches as the input variable approaches a specific point from either the left (values less than the point) or the right (values greater than the point).
Example:
For a piecewise function, checking the one-sided limit as for would give 0, while for would give -1.
One-sided Limits
The value a function approaches as its input approaches a specific point from either the left (below) or the right (above) side only.
Example:
For a piecewise function like , the one-sided limit as x approaches 0 from the left is -1, and from the right is 1.
One-sided limit
The value a function approaches as the input variable approaches a specific point from either the left side (values less than the point) or the right side (values greater than the point).
Example:
For , the one-sided limit as x approaches 0 from the right () is positive infinity, while from the left () it's negative infinity.
Oscillates
Describes a function that fluctuates rapidly between different values without settling on a single value as the input approaches a certain point.
Example:
The function oscillates infinitely many times between -1 and 1 as x approaches 0, preventing a limit from existing.
Piecewise Function
A function defined by multiple sub-functions, each applicable over a specific interval of the domain.
Example:
A common example of a piecewise function is , which behaves differently on either side of .
Quotient
The result obtained when one number or quantity is divided by another.
Example:
In the expression , the entire fraction represents a quotient of two polynomial expressions.
Quotient (function)
A function expressed as the ratio of two other functions, where vertical asymptotes often occur at points where the denominator becomes zero.
Example:
The function is a quotient function, and its denominator becoming zero at suggests a potential vertical asymptote.
Reciprocal
The multiplicative inverse of a number or expression, obtained by dividing 1 by that number or expression.
Example:
The reciprocal of is , which is useful when finding limits at infinity.
Right-hand limit
The value a function approaches as the input variable approaches a specific point from values greater than that point.
Example:
For the function , the right-hand limit as is 1.
Simplifying (to find limits)
A technique used when direct substitution yields an indeterminate form, involving algebraic manipulation (like factoring and canceling) to transform the function into an equivalent form where substitution works.
Example:
To find , you can use simplifying by factoring the numerator to , canceling , and then substituting into to get 4.
Squeeze Theorem
A mathematical theorem used to determine the limit of a function by comparing it to two other functions whose limits are known and equal at a specific point.
Example:
If you can show that and both and approach 5 as approaches 2, then by the Squeeze Theorem, must also approach 5.
Substitution
A direct method to evaluate limits by replacing the variable with the value it approaches, primarily effective for continuous functions.
Example:
To find the limit of as approaches 3, you can use substitution to get .
Surds
Expressions that contain irrational roots, typically square roots, that cannot be simplified to a rational number.
Example:
Numbers like , , or (which simplifies to ) are examples of surds.
Table (of values)
An organized display of numerical data showing function outputs for various inputs, used to estimate the behavior of a function near a specific point.
Example:
By examining a table of values for as gets closer to 0, you can estimate that its limit is 1.
Trigonometric Identity
An equation involving trigonometric functions that is true for all values of the variables for which the functions are defined. They are essential tools for simplifying expressions and solving equations.
Example:
To simplify for a limit problem, you would use the trigonometric identity to replace with .
Trigonometric Limit Theorem ((cos x - 1) / x)
A fundamental theorem stating that the limit of $\frac{\cos x - 1}{x}$ as $x$ approaches 0 is 0. This theorem is often used in conjunction with other limit properties.
Example:
When faced with , you can rearrange it to utilize this specific Trigonometric Limit Theorem.
Trigonometric Limit Theorem (sin x / x)
A fundamental theorem stating that the limit of $\frac{\sin x}{x}$ as $x$ approaches 0 is 1. This is crucial for evaluating many indeterminate trigonometric forms.
Example:
To find , you can manipulate the expression to apply the Trigonometric Limit Theorem for .
Two-sided Limits
The value a function approaches as its input approaches a specific point from both the left and the right sides. For this limit to exist, the corresponding one-sided limits must be equal.
Example:
If a function smoothly approaches 5 as x gets closer to 2 from both directions, then its two-sided limit at x=2 is 5.
Unbounded
Describes a function whose values increase or decrease without limit (to positive or negative infinity) as the input approaches a certain point.
Example:
The function is unbounded as x approaches 0, shooting up towards positive infinity.
Unbounded
Describes a function's behavior where its output values increase or decrease without limit, often occurring near vertical asymptotes.
Example:
As approaches 0, the function becomes unbounded, meaning its values shoot up towards positive infinity.
Vertical Asymptote
A vertical line that the graph of a function approaches but never touches or intersects as the input variable approaches a certain value where the function has an infinite limit.
Example:
The line x = 2 is a vertical asymptote for the function , indicating the function's values become unbounded near x = 2.
Vertical Asymptote
A vertical line where a function's graph approaches infinity or negative infinity as the input (x) approaches a specific finite value.
Example:
The function has a vertical asymptote at , because the function's values become infinitely large or small as gets closer to 5.