A linear mapping, also known as a linear transformation, is a function between two vector spaces that preserves the operations of vector addition and scalar multiplication. In other words, it maps a vector from one space to another in a way that maintains the structure of the vector space. Linear mappings are fundamental in linear algebra and are used to describe various mathematical concepts and relationships in a geometrically meaningful way. They play a crucial role in solving systems of linear equations, studying eigenvalues and eigenvectors, and understanding the properties of matrices. **

Yes, the mapping is left-unique. This means that each input value in the domain is associated with only one output value in the range. In other words, no two different input values can map to the same output value. This ensures that the mapping is well-defined and unambiguous. **

A mapping is proportional when there is a constant ratio between the corresponding values of the two sets being mapped. In other words, if the ratio of the output values to the input values remains constant, then the mapping is considered proportional. This means that as one set of values increases or decreases, the other set of values changes in direct proportion. **

MIDI mapping allows users to assign specific MIDI messages to control parameters within a software or hardware device. This process involves selecting a parameter to be controlled, such as volume or effects, and then assigning a MIDI message, such as a note, controller, or program change, to that parameter. Once the mapping is set up, the MIDI message can then be sent from a MIDI controller, such as a keyboard or pad controller, to manipulate the assigned parameter in real-time. This allows for a more hands-on and customizable approach to controlling music software and hardware. **

An identical mapping is a type of mapping where each element in one set is paired with a unique element in another set, such that the pairing preserves the identity of the elements. In other words, each element in the first set corresponds to only one element in the second set, and vice versa. This type of mapping is often used in mathematics and computer science to establish a one-to-one correspondence between elements of two sets. **

A bijective mapping is a function between two sets that is both injective and surjective. In other words, every element in the domain is paired with a unique element in the codomain, and every element in the codomain is paired with at least one element in the domain. This means that there is a one-to-one correspondence between the elements of the two sets. Bijective mappings are also known as one-to-one and onto functions. **

Online payments can be secure if proper security measures are in place. This includes using secure websites with encryption, using trusted payment processors, and being cautious with sharing personal and financial information. It's important to look for the "https" in the website URL and a lock symbol in the address bar to ensure the website is secure. Additionally, using strong and unique passwords for online accounts can also help enhance security. **

This mapping is not proportional because the size of the countries on the map does not accurately represent their actual land area. For example, Greenland appears much larger than it actually is in relation to other countries. This distortion occurs because the map uses the Mercator projection, which distorts the size of land masses as they get further from the equator. As a result, countries near the poles appear much larger than they are in reality. **