1.float: The built-in standard data type is decimal. 2. Input: keyboard input. 3. Print: output to. 4.%d and x%. 5. The function of single quotation marks: indicating characters. 6.* and * *: As operators, one is the multiplication symbol, and two * are connected to represent the root. 7.%0.3f Adjust the format of %area, where f stands for floating point number and 0.3 stands for 3 decimal places. 8. Parentheses.

Trigonometric formula is an identity expressed by trigonometric functions such as sin(3x), cos(3x) and the corresponding single-angle trigonometric functions, which is applied to mathematics, physics, astronomy and other disciplines.

Python is a widely used explanatory, high-level and general-purpose programming language, which was founded by GuidovanRossum of the Netherlands Institute of Mathematics and Computer Science. The first edition was published in 199 1. It is the successor of ABC language, and can also be regarded as a Python in LISP dialect using traditional infix expressions, which provides efficient advanced data structures and simple and effective object-oriented programming.