A public key is a type of key in asymmetric key encryption algorithms. It comes with a unique pair of a public key and a private key. The public key can be shared openly and is used to encrypt data or verify digital signatures, while the private key is kept secret by the user and is used for decryption or signing.
Looking down from a high place is often used to describe observing things below from above, like when a house is built on a small hill overlooking a river.
In math class, when solving a quadratic equation, you can directly plug the coefficients into the quadratic formula to get the result. This method is called the formula method and is where many people first encounter formulas. But the meaning of a formula goes far beyond that; it's a universal tool for expressing patterns and simplifying calculations across different fields. Whether in scientific computations or everyday office work, you can see formulas in action.
Negative correlation refers to the phenomenon where two variables move in opposite directions—when one goes up, the other goes down.
The metric system, also known as the meter system, is an internationally used measurement system based on decimal units and is also the foundation of the modern International System of Units (SI).
Negative integers are all the integers less than 0, like -1, -2, -3, and they are located to the left of 0 on the number line.
Math estimation is a method of quickly figuring out results through approximate calculations instead of getting the exact answer. It's mainly used to quickly judge situations or solve problems where precise calculation isn’t necessary.
Estimating area mainly depends on whether the shape is regular or not. The most common methods are the grid-counting method and the approximate conversion method. Choosing the right method based on the situation can quickly give you a rough value.
Compound measurement mainly refers to a method in industrial precision inspection where multiple detection technologies, like contact probes and optical imaging, are installed on the same device to collect comprehensive data from a workpiece. This approach allows the dimensional, shape, and positional error inspections of complex parts to be completed on one machine without repeatedly disassembling the workpiece, making it both fast and accurate. Besides the industrial field, social sciences and surveying also have their own concepts of "compound measurement," but the meanings are different.