Glossary
Accumulation Function
A function that calculates the total change or quantity accumulated over an interval, starting from a fixed point and ending at a variable point.
Example:
If a baker starts with 0 dough and adds flour at a rate of 100g per minute, the accumulation function would tell you the total amount of dough at any given time 'x'.
Accumulation Function
A function defined as an integral where the upper limit is a variable, representing the accumulated quantity of a rate over an interval.
Example:
If represents the total amount of water accumulated in a tank from time 0 to , then is an accumulation function.
Accumulation of Change
The total change in a quantity over a specified interval, determined by its rate of change. It represents the net effect of the rate over time or another independent variable.
Example:
If a car's speed (rate of change of distance) is 60 km/h for 2 hours, the accumulation of change in distance is 120 km.
Accumulation of Change
This refers to the total amount by which a quantity has changed over an interval, calculated by integrating its rate of change.
Example:
If a company's profit rate is dollars per day, then represents the total accumulation of change in profit over a month.
Accumulation of Change
The total amount by which a quantity has increased or decreased over a specific interval, often calculated by integrating a rate of change.
Example:
If a reservoir's water level changes by a certain rate each day, the accumulation of change over a week would be the total rise or fall in water level during that week.
Accumulation of change
Represents the total change in a quantity over an interval, often found by integrating a rate of change.
Example:
If you know the rate at which water is flowing into a tank, the accumulation of change would tell you the total volume of water added over a specific time period.
Adjacent Intervals Property
This property allows an integral over a larger interval to be broken down into a sum of integrals over adjacent sub-intervals.
Example:
If you need to find the total area under a curve from to , you can use the adjacent intervals property to calculate it as .
Antiderivative
A function $F(x)$ whose derivative is the original function $f(x)$, meaning $F'(x) = f(x)$.
Example:
If , then is an antiderivative of , where C is any constant.
Antiderivative
A function $F(x)$ whose derivative is the original function $f(x)$, meaning $F'(x) = f(x)$. It's the reverse process of differentiation.
Example:
If the velocity of a particle is , then its position function is an Antiderivative, as differentiating gives .
Area (under a curve)
The region bounded by a function's graph, the x-axis, and two vertical lines, whose measure is approximated by methods like trapezoidal sums.
Example:
Finding the area under the curve of a power output function over time would give the total energy consumed.
Area Under the Curve
This is a geometric interpretation of a definite integral, representing the region bounded by the function's graph, the x-axis, and the vertical lines at the limits of integration.
Example:
If you integrate from to , the result is the area under the curve of the parabola from the origin to .
Area Under the Rate of Change Curve
The graphical representation of the accumulation of change. The area between the graph of a rate of change function and the x-axis over an interval directly corresponds to the total change in the quantity over that interval.
Example:
If a graph shows the flow rate of water into a pool, calculating the area under the rate of change curve from t=0 to t=30 minutes tells you the total volume of water added in that half-hour.
Boundary Value
A known initial or specific value of a quantity at a particular point in time or at a specific independent variable value. It's used to determine the total value after an accumulation of change.
Example:
If a bank account starts with $1000, that's the boundary value before any interest accrues or withdrawals are made.
Concave Down
A characteristic of a function where its graph curves downwards, meaning its slope is decreasing over an interval.
Example:
A function like is concave down, indicating that a trapezoidal sum will underestimate the area under its curve.
Concave Up
A characteristic of a function where its graph curves upwards, meaning its slope is increasing over an interval.
Example:
For a function like , it is concave up over its entire domain, which means a trapezoidal sum will overestimate its area.
Constant Multiple Property
This property states that a constant factor within an integral can be moved outside the integral sign without changing the result.
Example:
The integral can be simplified to using the constant multiple property, making calculations easier.
Constant of Integration
The arbitrary constant 'C' added to the antiderivative of a function when performing indefinite integration, accounting for the loss of information about constant terms during differentiation.
Example:
When finding the antiderivative of , we get ; the Constant of Integration 'C' signifies that any constant term would vanish upon differentiation.
Continuous Function
A function whose graph can be drawn without lifting the pen, meaning it has no breaks, jumps, or holes in its domain.
Example:
The function is a continuous function over all real numbers, unlike a step function which has jumps.
Decreasing (function)
A function is decreasing on an interval if its output values (y-values) consistently fall as its input values (x-values) increase.
Example:
The function for is a decreasing function, as its graph goes down from left to right in that region.
Definite Integral
A mathematical tool used to calculate the exact area under a curve between two specific points on the x-axis. In the context of rates, it computes the accumulation of change.
Example:
To find the total distance traveled by a rocket given its velocity function from launch to 10 seconds, you would use a definite integral of the velocity function from t=0 to t=10.
Definite Integral
The exact value of the net area between a function's curve and the x-axis over a specified interval, representing the total accumulation of a quantity.
Example:
Calculating the definite integral of a velocity function over a time interval gives the exact displacement of an object.
Definite Integral
A definite integral calculates the net accumulation of a quantity or the signed area under the curve of a function over a specified interval, resulting in a single numerical value.
Example:
If a car's velocity is given by m/s, the definite integral would tell you the total distance traveled by the car in the first 5 seconds.
Definite Integral
An integral with specified upper and lower limits, used to calculate the net change or area under a curve over a given interval.
Example:
To find the total work done by a variable force from point A to point B, you would use a definite integral of the force function over that distance.
Definite Integral
An integral evaluated over a specific interval $[a, b]$, representing the net signed area between the function's graph and the x-axis over that interval.
Example:
Calculating the total displacement of a car from time to seconds, given its velocity function, involves computing a definite integral.
Definite Integral
The exact accumulation of quantities over an interval, often represented as the precise area under a curve between two specific points.
Example:
The definite integral of a velocity function over a time interval gives the exact displacement of an object during that time.
Definite Integral
An integral with specified upper and lower limits, resulting in a numerical value that represents the net signed area under a curve over a given interval.
Example:
Calculating the total distance traveled by a car with varying speed over a specific time period involves evaluating a Definite Integral of its velocity function.
Dummy Variable
A placeholder variable used within an integral (e.g., 't') that does not affect the final value of the integral, especially when the limits of integration are variables.
Example:
In , 't' is the dummy variable used to perform the integration, while 'x' remains the variable of the resulting function.
First Fundamental Theorem of Calculus
This theorem provides a straightforward method for evaluating definite integrals by connecting them to antiderivatives.
Example:
To find the exact area under the curve of from to , you'd use the First Fundamental Theorem of Calculus by finding its antiderivative and calculating .
Fixed Starting Point (a)
The constant lower limit of integration in a definite integral, indicating where the accumulation begins.
Example:
In the integral , the number 2 is the fixed starting point (a).
Fundamental Theorem of Calculus
A crucial concept in calculus that establishes the profound connection between differentiation and integration.
Example:
Understanding the Fundamental Theorem of Calculus allows you to solve problems that involve both rates of change and total accumulation, like finding the total distance traveled from a velocity function.
Fundamental Theorem of Calculus
A foundational theorem that links the concepts of differentiating a function and integrating a function, providing a method to evaluate definite integrals using antiderivatives.
Example:
Using the Fundamental Theorem of Calculus, you can quickly find the exact area under the curve of from 0 to 1 by evaluating its antiderivative at those points.
Given Starting Point
The fixed initial value or lower limit from which the accumulation or integration begins.
Example:
When calculating the total distance traveled by a car, the odometer reading at the beginning of the trip serves as the given starting point.
Heights (of a trapezoid/function values)
The vertical lengths of the parallel sides of a trapezoid, determined by the function's value at the endpoints of each subinterval.
Example:
The heights of the trapezoids are crucial because they represent the function's magnitude at the specific x-values, directly influencing the area calculation.
Increasing (function)
A function is increasing on an interval if its output values (y-values) consistently rise as its input values (x-values) increase.
Example:
The function is an increasing function over all real numbers, meaning its graph always goes up from left to right.
Indefinite Integral
An integral without specified upper and lower limits, representing the family of all possible antiderivatives of a given function, denoted by $F(x) + C$.
Example:
Finding the Indefinite Integral of gives , representing all functions whose derivative is .
Integrand
The function $f(x)$ that is being integrated within an integral expression, typically written after the integral symbol.
Example:
In the integral , is the Integrand, the function whose area under the curve is being found.
Integrand ($f(x)$)
The integrand is the function being integrated within a definite integral, denoted as $f(x)$ in the expression $\int_{a}^{b} f(x) \, dx$.
Example:
In the integral , the integrand is , which is the function whose area or accumulation we are finding.
Integration Variable ($dx$)
The integration variable, typically $dx$, indicates with respect to which variable the integration is performed, defining the axis along which the accumulation is measured.
Example:
For , the integration variable is , meaning we are integrating with respect to , not or any other variable.
Interval
The specified range $[a, b]$ over which a definite integral is evaluated, defined by its lower and upper limits.
Example:
When calculating the work done by a variable force from meter to meters, the Interval of integration is .
Left Riemann Sum
A type of Riemann sum where the height of each approximating rectangle is determined by the function's value at the left endpoint of its corresponding subinterval.
Example:
When approximating the area under from to using four rectangles, the first rectangle's height would be , demonstrating a Left Riemann Sum.
Limits of Integration ($a$ and $b$)
These are the upper ($b$) and lower ($a$) bounds of the interval over which the function is integrated, defining the specific range for accumulation.
Example:
In , the limits of integration are and , meaning we are calculating the net area from to .
Lower Limit
The bottom value 'a' in a definite integral ${\int }_{a}^{b}f(x) \, dx$, indicating the starting point of the interval over which the integration is performed.
Example:
In , the value 0 is the Lower Limit, defining the leftmost boundary of the area being calculated.
Midpoint Riemann Sum
A type of Riemann sum where the height of each approximating rectangle is determined by the function's value at the midpoint of its corresponding subinterval.
Example:
When calculating the average temperature over a day, a Midpoint Riemann Sum would use the temperature reading from the middle of each hour to represent that hour's average.
Negative Rate of Change
Occurs when the rate of change function's graph is below the x-axis, indicating that the quantity is decreasing over that interval. The accumulation of change will be negative.
Example:
If the temperature of a cooling object is dropping, it exhibits a negative rate of change in temperature.
Overestimate
An approximation that yields a value greater than the true value, occurring in trapezoidal sums when the function is concave up.
Example:
If you use a trapezoidal sum to approximate the area under a concave up curve, your result will be an overestimate of the true area.
Overestimate
An approximation that yields a value greater than the true or exact value, often occurring when the approximating rectangles extend above the curve.
Example:
For a decreasing function, a Left Riemann Sum will typically result in an overestimate of the true area under the curve.
Positive Rate of Change
Occurs when the rate of change function's graph is above the x-axis, indicating that the quantity is increasing over that interval. The accumulation of change will be positive.
Example:
When a company's profit is growing, it has a positive rate of change in profit, meaning more money is being earned.
Rate of Change
The speed or pace at which a quantity is changing with respect to another quantity, often time. It indicates how quickly a value is increasing or decreasing.
Example:
A factory produces 50 widgets per hour; this is its rate of change of production.
Rate of Change (Interpretation)
When the integrand represents a rate of change, the definite integral provides the total accumulated change of the original quantity over the given interval.
Example:
If is the rate at which water flows into a tank in liters per minute, then gives the total volume of water accumulated in the tank over the first 10 minutes, illustrating the rate of change interpretation.
Rate of Change Function
A function that describes how one quantity changes with respect to another, often represented as the derivative of an accumulation function.
Example:
If a population grows at a certain number of individuals per year, that growth rate is the rate of change function for the population.
Reversing Limits Property
This property states that reversing the upper and lower limits of integration changes the sign of the definite integral.
Example:
If , then due to the reversing limits property.
Riemann Sum
A Riemann sum is an approximation of the definite integral of a function, calculated by summing the areas of a finite number of rectangles under the curve.
Example:
To estimate the area under from to , one could use a Riemann sum with 4 rectangles, calculating the sum of their areas to get an approximation.
Riemann sum
A technique for approximating the exact value of an accumulation of change, such as a definite integral or the area under a curve, by summing the areas of multiple rectangles.
Example:
To estimate the total distance a car traveled given its varying speed over time, one could use a Riemann sum by adding up the areas of rectangles representing speed multiplied by small time intervals.
Right Riemann Sum
A type of Riemann sum where the height of each approximating rectangle is determined by the function's value at the right endpoint of its corresponding subinterval.
Example:
To approximate the total work done by a variable force, a Right Riemann Sum might use the force at the end of each small displacement interval to calculate the work for that segment.
Second Fundamental Theorem of Calculus
This theorem states that the derivative of an integral with respect to its upper limit is the original function itself.
Example:
If you have a function defined as , the Second Fundamental Theorem of Calculus immediately tells you that .
Signed Area
The definite integral represents the signed area, where areas above the x-axis are considered positive and areas below the x-axis are considered negative.
Example:
For from to , the integral because the positive area above the x-axis from to and to is cancelled out by the negative area below the x-axis from to , demonstrating the concept of signed area.
Subinterval
A subinterval is one of the smaller divisions of the total integration interval $[a, b]$, used in the construction of Riemann sums to approximate the area under a curve.
Example:
If you're integrating from to and divide the interval into 5 equal parts, each part like or is a subinterval.
Subinterval
A smaller division of a larger interval, used in Riemann sums to define the base of each approximating rectangle.
Example:
If you're estimating the area under a curve from to , you might divide it into five subintervals like .
Subintervals
Smaller, contiguous intervals into which a larger interval is divided to facilitate the approximation of an integral, with each subinterval forming the base of a trapezoid.
Example:
To get a more accurate approximation of an integral, you would typically divide the main interval into a greater number of subintervals.
Sum/Difference Property
This property allows the integral of a sum or difference of functions to be split into the sum or difference of their individual integrals.
Example:
To integrate from to , you can use the sum/difference property to evaluate separately.
Trapezoidal Sum
A numerical integration method that approximates the definite integral of a function by dividing the area under its curve into a series of trapezoids and summing their areas.
Example:
To estimate the total distance a car traveled given its speed at various times, you could use a trapezoidal sum on the speed-time graph.
Trapezoids
Four-sided polygons with at least one pair of parallel sides, used as the fundamental geometric shapes in a trapezoidal sum to approximate the area under a curve.
Example:
When approximating the area under a curve, each segment is treated as a trapezoid where the parallel sides are the function values at the interval endpoints.
Underestimate
An approximation that yields a value less than the true value, occurring in trapezoidal sums when the function is concave down.
Example:
When approximating the area under a concave down curve using a trapezoidal sum, the calculated value will be an underestimate of the actual area.
Underestimate
An approximation that yields a value less than the true or exact value, often occurring when the approximating rectangles lie entirely below the curve.
Example:
For an increasing function, a Left Riemann Sum will typically result in an underestimate of the true area under the curve.
Units of Accumulation
The resulting units of the accumulated quantity, derived by multiplying the units of the rate of change by the units of the independent variable. This ensures dimensional consistency.
Example:
If a population grows at a rate of 'people per year' over 'years', the units of accumulation will be 'people', representing the total change in population.
Upper Limit
The top value 'b' in a definite integral ${\int }_{a}^{b}f(x) \, dx$, indicating the endpoint of the interval over which the integration is performed.
Example:
In , the value 5 is the Upper Limit, defining the rightmost boundary of the area being calculated.
Variable Ending Point (x)
The upper limit of integration in an accumulation function, which is a variable that determines the extent of the accumulation.
Example:
When calculating the volume of water flowing into a tank over time, 'x' represents the variable ending point (x), allowing you to find the volume at any future moment.
Variable Endpoint
The changing upper limit of an interval, typically represented by a variable (e.g., 'x'), up to which accumulation is measured.
Example:
In a function describing the total rainfall over time, 'x' represents the variable endpoint, allowing you to find the total rainfall up to any specific day.
Width (of a trapezoid/subinterval)
The horizontal length of a subinterval, which serves as the base of a trapezoid in the trapezoidal sum calculation.
Example:
In a trapezoidal sum with equal width subintervals, the total interval length is simply divided by the number of trapezoids.
Zero-Length Interval Property
This property states that the definite integral of any function over an interval where the upper and lower limits are identical is always zero.
Example:
If you integrate from to , the result is because of the zero-length interval property, as there is no area over a single point.