A questionnaire survey refers to a method where you create a detailed and thorough questionnaire and ask respondents to answer it to collect information.
math
If 'survey' refers to a statistical method (like sampling surveys), then it falls under a specific term in applied statistics.
Electromagnetism is an important branch of physics that studies electric charges, currents, electric fields, magnetic fields, and how they interact. Its core theoretical framework is described by Maxwell's equations and it’s widely used in everything from power systems to modern communications.
Cartesian coordinates are a math tool used to determine the position of points with numbers, usually referring to the rectangular coordinate system. It was created by the French mathematician Descartes, and the main idea is to link geometric shapes with algebraic equations, making calculations easier.
René Descartes was a famous French philosopher, mathematician, and physicist. He is one of the founders of modern Western philosophy. He made important contributions to the development of modern mathematics and is considered the father of analytic geometry for formalizing the coordinate system in geometry.
The 'Cartesian network' in math usually refers to an interconnection network built through the Cartesian product of graphs, not the Cartesian coordinate system itself; the latter is often mistakenly called a 'Cartesian network,' but it's actually a 'Cartesian coordinate grid'.
René Descartes (also often translated as Descartes) was a French philosopher, mathematician, and physicist born on March 31, 1596, and passed away on February 11, 1650. He's commonly called the 'father of modern science.' His most famous quote is 'I think, therefore I am,' and he also invented the Cartesian coordinate system that we often use in math class.
An isosceles trapezoid is a special type of trapezoid with equal legs. It's a symmetrical shape, with one pair of opposite sides parallel but not equal, and the other pair not parallel but equal in length. It's a common shape you come across when learning geometry.
An isosceles triangle is a triangle that has at least two equal sides. The two equal sides are called the legs, and the other side is called the base. The angle between the legs is called the vertex angle, and the angles between a leg and the base are called the base angles. When solving related problems, if the problem doesn't specify which side is the leg or the base, you usually need to consider different cases.
An arithmetic sequence is a sequence where, starting from the second term, the difference between each term and the previous one is the same constant. This fixed difference is called the common difference, usually represented by the letter d. For example, the common odd number sequence 1, 3, 5, 7... has a difference of 2 between each pair of consecutive numbers, which makes it an arithmetic sequence with a common difference of 2.