One: (very general) refers to the sum of the numbers listed in a conic curve (such as ellipse, the length of semi-major axis). In the quadratic formula of linear coefficient of general formula x, X 2 is a coefficient and a trigonometric function can be in amplitude.
B is the oblique or vertical intercept representation of the linear correlation coefficient y: (and similar), and the quadratic function is the conic band of the x coefficient (such as ellipse, long semi-short axis).
C: (and similar) Constant term of conic quadratic function expression
D: 2 or the distance between points indicates a straight line, tolerance.
Arithmetic progression in e: natural logarithm, eccentricity of quadratic curve (E = C/A)
F, g, h: generally represents a function.
Me: complicated (fictional) reasons (what I forgot) stipulate that I 2 =- 1.
Reporter: I'm not used to it. .
K is the slope.
L: stands for straight line (such as l 1: y = x+ 1, L2: y =-x+ 1, etc.). ).
M: Unknown constant is set (multiple letters can be used).
N is the number of columns.
Type o: probability
Q: Coordinate system
The common ratio r radius of the origin of p
Area, number of columns and
T: (unclear)
U, v: stands for a function (f, g, h has ..., and u and v are used).
Volume w: use plural numbers to indicate specific complexity.
X, y, z: unknown
In addition, all uppercase letters can represent a base point, lowercase letters plus an arrow vector can represent it, many unknown letters can also represent it, and so on.