沪科版七年级下册数学知识点总结

2024年4月10日发(作者：罗定中学初一数学试卷分析)

沪科版七年级下册数学知识点总结

Chapter 6 Real Numbers in Grade 7 Mathematics

1) Square Roots and Cube Roots

Roots

1) n: Generally。if the square of a number is equal to a。then

this number is called the square root of a。also known as the

second root。If x2 = a。then x is called the square root of a。

denoted by \"±a\"。and a ≥ is。x = ±a.

2) n: The square root of a non-negative number a is denoted

by ±a。read as \"positive or negative square root of a\" (a is called

the radicand)。

3) Properties: A positive number has two square roots。which

are opposite to each other。the square root of 0 is 0.a negative

number does not have a square root.

4) Square Root: The n of finding the square root is called

taking the square root.

Ⅰ。The square root is the result of taking the square root。

Ⅱ。Taking the square root and squaring are inverse ns.

etic Square Roots

1) n: The positive square root of a positive number a is called

the arithmetic square root of a。The arithmetic square root of a is

denoted by \"a\"。and a ≥ is。x = a.

2) Properties: (1) The arithmetic square root of a number a is

non-negative。that is。a ≥ 0 always holds。(2) A positive number

has only one arithmetic square root。which is positive。the

arithmetic square root of 0 is 0.a negative number does not have an

arithmetic square root.

are the square root formulas?

a(a>0)

2①a2=a=

a(a<0)

0(a=0)②(a)=a(a≥0)

the square of 1120: 112 = 121.122 = 144.132 =

169.142 = 196.152 = 225.162 = 256.172 = 289.182 = 324.192 =

361.202 = 400.

1.2 are approximately equal to 1..1.7325.2.236.

Roots: