B: (similar to A) The straight line is the coefficient of Y, or the longitudinal intercept on the inclined section, and the quadratic function is the coefficient of X, and the conic curve (such as the semi-short axis length of an ellipse, etc.) is used. ).
C: (Similar to A) Conic curves use constant terms in quadratic function expressions.
D: Represents the distance between two points or between a point and a straight line, and the tolerance in arithmetic progression.
E: base of natural logarithm, eccentricity of quadratic curve (e=c/a)
F, g, h: generally represents a function.
I: I 2 =-1in the complex number (imaginary number)
J: Not too much. ..
K: slope of straight line
L: represents a straight line (e.g. l 1: y = x+ 1, L2: y =-x+ 1).
M: Unknown constant set (multiple letters can be used)
N: the number of items in the sequence.
O: origin in coordinate system
probability;likelihood
Q: Common proportions in geometric series.
R: the radius of the circle
S: area, a series of sums.
T: (uncertain)
U, V: Represents a function (F, G, H is available, so U and V...)V can also represent volume.
W: Used in the plural, indicating a special plural.
X, y, z: unknown number.
Also, all uppercase letters can basically represent a point, an arrow at the beginning of lowercase letters can represent a vector, many letters can be used when setting unknowns, and so on.