objective function
(noun)
A function to be maximized or minimized in optimization theory.
Examples of objective function in the following topics:
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Application of Systems of Inequalities: Linear Programming
- The function to be maximized (the objective function, and in this case, the profit on the chairs) is:
- Standard form also requires the objective function to be a minimization.
- If the problem calls for maximization, multiply the objective function by $-1$.
- where the first row defines the objective function and the remaining rows specify the constraints.
- Therefore, the objective function is unbounded.
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Symmetry of Functions
- Two objects have symmetry if one object can be obtained from the other by a transformation.
- Two objects are symmetric to each other with respect to the invariant transformations if one object is obtained from the other by one of the transformations.
- In the case of symmetric functions, determining symmetry is as easy as graphing the function or evaluating the function algebraically.
- Symmetry of a function can be a simple shift of the graph (transformation) or the function can be symmetric about a point, line or axes.
- Functions and relations can be symmetric about a point, a line, or an axis.
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Applications of the Parabola
- What Galileo discovered and tested was that when gravity is the only force acting on an object, the distance it falls is directly proportional to the time squared.
- For objects extended in space, such as a diver jumping from a diving board, the object follows a complex motion as it rotates, while its center of mass forms a parabola.
- This is because air resistance is a force acting on the object, and is proportional to the object's area, density, and speed squared.
- For dense objects, and/or at low speeds, the air resistance force is small.
- All of the physical examples are situations where an object's trajectory or the shape of an object fits a generalized parabola function:
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Recursive Definitions
- A recursive definition of a function defines its values for some inputs in terms of the values of the same function for other inputs.
- In mathematical logic and computer science, a recursive definition, or inductive definition, is used to define an object in terms of itself.
- A recursive definition of a function defines values of the functions for some inputs in terms of the values of the same function for other inputs.
- For example, the factorial function $n!
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Scientific Applications of Quadratic Functions
- If any of the variables $a$, $b$, or $c$ represent functions in themselves, it is often useful to expand the terms, combine like variables, and then re-factor the expression.
- Consider the equation relating gravitational force ($F$) between two objects to the masses of each object ($m_1$ and $m_2$) and the distance between them ($r$):
- The shape of this function is not a parabola, but becomes such a shape if rearranged to solve for $m_1$ or $m_2$, as seen below:
- Substituting any time ($t$) in place of $t_h$ leaves the equation for height as a quadratic function of time.
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Functions and Their Notation
- We write the function as:$f(-3)=9$.
- In the case of a function with just one input variable, the input and output of the function can be expressed as an ordered pair.
- Let's say the machine has a blade that slices whatever you put in into two and sends one half of that object out the other end.
- All functions are relations, but not all relations are functions.
- Connect the notation of functions to the notation of equations and understand the criteria for a valid function
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Transformations of Functions
- A reflection of a function causes the graph to appear as a mirror image of the original function.
- Let the function in question be $f(x) = x^5$.
- A rotation is a transformation that is performed by "spinning" the object around a fixed point known as the center of rotation.
- Where $x_1$and $y_1$are the new expressions for the rotated function, $x_0$ and $y_0$ are the original expressions from the function being transformed, and $\theta$ is the angle at which the function is to be rotated.
- If we rotate this function by 90 degrees, the new function reads:
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Models Involving Nonlinear Systems of Equations
- Its position in meters (y) can be determined as a function of time in seconds (t), by the formula:
- Its position (y) in meters can be determined as a function of time (t) in seconds, using the following formula:
- To express the position of the second car relative to the first as a function of time, we can modify the second equation as such:
- The kinetic energy of the objects depends on the speed squared, and the momentum depends on the speed directly.
- Rendering and visualizing these objects, and formulating a plan for constructing them, requires the software to solve nonlinear systems.
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Introduction to Sequences
- A mathematical sequence is an ordered list of objects, often numbers.
- In mathematics, a sequence is an ordered list of objects.
- A more formal definition of a finite sequence with terms in a set $S$ is a function from $\left \{ 1, 2, \cdots, n \right \}$ to $S$ for some $n > 0$.
- An infinite sequence in $S$ is a function from $\left \{ 1, 2, \cdots \right \}$ to $S$.
- For example, the sequence of prime numbers $(2,3,5,7,11, \cdots )$ is the function $1→2, 2→3, 3→5, 4→7, 5→11, \cdots$ .
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Introduction to Rational Functions
- A rational function is one such that $f(x) = \frac{P(x)}{Q(x)}$, where $Q(x) \neq 0$; the domain of a rational function can be calculated.
- A rational function is any function which can be written as the ratio of two polynomial functions.
- Any function of one variable, $x$, is called a rational function if, and only if, it can be written in the form:
- Note that every polynomial function is a rational function with $Q(x) = 1$.
- A constant function such as $f(x) = \pi$ is a rational function since constants are polynomials.