1, elevation refers to the angle measured from the baseline or horizontal plane, and is usually used to describe the perspective from bottom to top. For example, if we look up at the starry sky, looking up here is the image expression of elevation. If an object rises relative to the horizontal plane or horizon, its elevation angle will also increase accordingly.
2. The depression angle is opposite to the elevation angle, which refers to the angle measured from the baseline or horizontal plane. Often used to describe a top-down perspective. For example, overlooking the city panorama is the image expression of the depression angle. If an object is lowered relative to the horizontal plane or horizon, its depression angle will increase accordingly.
3. In practical application, elevation angle and depression angle are often used to describe and analyze the orientation and perspective relationship of spatial structures such as buildings, mountains and roads. In photography and video shooting, photographers often create specific visual effects by controlling the angle, such as capturing a wider scene with a wide-angle lens or creating a visual effect with a long lens.
The essence of mathematics:
1, abstract: Mathematics is a subject that abstracts, generalizes and summarizes specific things. It uses symbols, formulas and algorithms to transform concrete things in the real world into mathematical models and concepts, so as to better understand and analyze their essential characteristics and laws. For example, the concepts of integer, decimal and percentage in mathematics are abstractions of various quantities in real life.
2. Logic: The basis of mathematics is logical reasoning, that is, using logical rules and methods to deduce and prove mathematical conclusions. In mathematics, every concept, theorem and inference must be proved to be correct by strict logical reasoning, thus establishing a complete mathematical system. For example, geometry and algebra in mathematics involve the application of logical reasoning.
3. Applicability: Mathematics is a widely used subject, which can be used to solve various practical problems. For example, the knowledge of probability statistics and linear algebra in mathematics can be applied to data analysis and machine learning to help people better understand and solve practical problems. Mathematics is also widely used in engineering, economy, biology and other fields.