1, sum cubic formula (A+B) 3 = A 3+3A 2B+3AB 2+B 3, difference cubic formula (A-B) 3 = A 3-3A 2B+3AB 2-B 3, cubic sum formula a3.

2. Square difference formula: (a+b) (a-b) = a 2-b 2. Complete square formula: a b 2 = a 2 2ab+b 2. Square root property: positive square root doesn't work, zero square root is still zero. There are two negative square roots with opposite signs and the same value. Arithmetic square root: negative square root doesn't work, zero square root is still zero. There are two positive square roots with opposite signs and the same value.

3. Absolute value: positive square root, zero square root or zero is not allowed. There are two negative square roots with opposite signs and the same value. Law of rational number subtraction: subtracting a number is equal to adding the reciprocal of this number; That is, a-b=a+(-b). The square difference formula of multiplication: the product of the sum of two numbers and the difference between these two numbers is equal to the square difference between these two numbers.

4. Addition rule of rational numbers: add two numbers with the same sign, take the same sign, and add the absolute values. Two numbers with different signs are added, and the sum is 0 when the absolute values are equal; When the absolute values are not equal, take the sign of the addend with the larger absolute value and subtract the smaller absolute value from the larger absolute value. Add a number to 0 and you still get the number.

5. Pythagorean theorem: the sum of squares of two right angles A and B of a right triangle is equal to the square of hypotenuse C, that is, A? +b？ =c？ . The nature of parallelogram: the opposite sides of parallelogram are equal and parallel; Diagonal angles of parallelogram are equal and adjacent angles are complementary; Diagonal bisection of parallelogram. Law of multiplication with the same base power: multiply with the same base power, the base number is unchanged, and the exponents are added.