In a monomial, the sum of the exponents of all the letters is called the degree of the monomial.

A nonzero degree is 0.

The coefficient of a single letter is 1.

Same radix power multiplication, constant radix, exponential addition.

Power, constant radix, exponential multiplication.

The power of the product is equal to each factor in the product multiplied by the power, and then multiplied by the power.

Same base powers divides, the base remains the same, and the exponent is subtracted.

Multiplying a polynomial by a monomial is to multiply each term of a polynomial by a monomial, and then add the products.

(a+b)(a-b)=a2-b2

(a+b) 2=a2+2ab+b2

(a-b) 2=a2-2ab+b2

Behavior lines and intersections:

The sum of two angles is a right angle, and these two angles are called complementary angles.

The sum of these two angles is a right angle, and these two angles are called complementary angles.

The same angle or the complementary angle of the same angle is equal.

The same angle or the complementary angle of the same angle is equal.

Two sides of one corner are opposite extension lines of two sides of another corner, and two corners like this are opposite vertex angles.

Homoclinic angle, internal dislocation angle and internal angle on the same side refer to two angles with special relationship, which appear in pairs.

The appearance of these three corners must have "three lines", that is, two lines are cut by a third line.

Isomorphic angle characteristics: the cutting lines are on the same side and the cutting lines are in the same direction.

Internal dislocation angle characteristics: on both sides of the cutting line, between two cutting lines.

Characteristics of the inner angle on the same side: the cutting lines are on the same side and cut between the two lines.

The same angle is equal and two straight lines are parallel.

Internal dislocation angles are equal and two straight lines are parallel.

The internal angles on the same side are equal, and the two straight lines are parallel.

These two straight lines are parallel and the included angle is equal.

Two straight lines are parallel and have equal internal angles.

These two lines are parallel and complementary.

Data in life:

The measurement results are all approximate.

Go to the nearest place and bypass the next place.

Approximate number of significant digits, mainly starting from the number whose first digit on the left is not 0, and then rounding to the last digit of the last significant digit. Larger numbers are expressed by scientific counting methods.

Probability:

Whether several people play games together is fair to all depends on whether the probability of winning is equal.

The probability of the inevitable event is 1, and it is recorded as p (inevitable event) = 1.

The probability of an impossible event is 0, and it is recorded as p (impossible event) = 1.

If a is an uncertain event, then 0

Triangle:

A graphic triangle composed of three line segments that are not on the same straight line.

The three line segments that make up a triangle are called the sides of the triangle; The common endpoint of two adjacent sides is called the vertex of a triangle; The included angle between two adjacent sides is called the inner angle of a triangle.

The sum of the internal angles of a triangle is 180 degrees.

Any triangle has at most three acute angles; At least two acute angles; There is at most one obtuse angle; There is at most one right angle.

In a triangle, the line segment connecting the vertex and its opposite side is called the center line of the triangle.

In a triangle, the bisector of the inner angle intersects its opposite side, and the line segment between the vertex and the intersection of this angle is called the bisector of the triangle.

A triangle has three bisectors, all of which are inside the triangle and intersect at one point.

The bisector of a triangle is a line segment and the bisector of an angle is a ray.

Draw a vertical line from the vertex of a triangle to the line where its opposite side is located. The line segment from the vertex to the vertical foot is called the high line of the triangle.

Congruent figures have the same shape and size.

The corresponding edges of congruent triangles are equal, and the corresponding angles are equal.

There are usually the following methods to find the corresponding edges and corners:

1. The opposite side of the corresponding angle of congruent triangles is the corresponding edge, and the edge sandwiched by two corresponding angles is the corresponding edge.

2. The diagonal of the corresponding side of congruent triangles is the corresponding angle, and the included angle of two corresponding sides is the corresponding angle.

3. If there is a male side, the male side is the corresponding side.

4. If there is a common angle, the common angle is the corresponding angle.

5. If there is an antipodal angle, the antipodal angle is the corresponding angle.

6. The longest side (or maximum angle) of two congruent triangles is the corresponding side (or corresponding angle), and the shortest side (or minimum angle) is the corresponding side (or corresponding angle).

Triangular congruence conditions: SSS, SAS, ASA, AAS.

The condition of congruence of right triangle: HL.