如何将数字表示为 2 的幂?
数学不仅与数字有关,而且与涉及数字和变量的不同计算有关。这就是基本上被称为代数的东西。代数被定义为涉及由数字、运算符和变量组成的数学表达式的计算的表示。数字可以是 0 到 9,运算符是数学运算符,如 +、-、×、÷、指数等,变量如 x、y、z 等。
指数和幂
指数和幂是数学计算中使用的基本运算符,指数用于简化涉及多次自乘的复杂计算,自乘基本上是数字与自身相乘。例如,7 × 7 × 7 × 7 × 7,可以简单地写成 7 5 。这里,7 是基值,5 是指数,值为 16807。11 × 11 × 11,可写为 11 3 ,这里,11 是基值,3 是 11 的指数或幂。 11 3是 1331。
指数被定义为一个数字的幂,它乘以自身的次数。如果表达式写成 cx y其中 c 是常数,c 将是系数,x 是底数,y 是指数。如果一个数 p 乘以 n 次,n 将是 p 的指数。它将被写为
p × p × p × p … n 次 = p n
指数的基本规则
为了求解指数表达式以及其他数学运算,为指数定义了一些基本规则,例如,如果有两个指数的乘积,则可以简化以使计算更容易,称为乘积规则,让我们看一下指数的一些基本规则,
- 乘积法则 ⇢ a n + a m = a n + m
- 商规则 ⇢ a n / a m = a n – m
- 幂律 ⇢ (a n ) m = a n × m或m √a n = a n/m
- 负指数规则 ⇢ a -m = 1/a m
- 零规则 ⇢ a 0 = 1
- 一条规则 ⇢ a 1 = a
如何将数字表示为 2 的幂?
解决方案:
Any number having a power of 2 can be written as the square of that number. The square of a number of a number is the number multiplied by itself, square of the number is represented as the exponent 2 on that number. If square of x has to be written, it will be x2. For instance, the square of 3 is represented as 52 and is equal to 5 × 5 = 25. Another example can be the square of 12, represented as 122, is equal to 12 × 12 = 144. Lets take the number 3, now 3 as the power of 2 will be represented as,
32 = 3 × 3
= 9
Therefore, 9 is the 2nd power of 3.
Hence, it can be concluded that any number as a power of 2 can be represented as the square of that number.
示例问题
问题 1:求解表达式 5 2 – 3 2 。
解决方案:
To solve the expression, first solve the 2nd powers on the numbers and then subtract the second term by the first term. However, the same problem can be solved in an easier way by simply applying a formula, the formula is,
x2 – y2 = (x + y)(x – y)
52 – 32 = (5 + 3)(5 – 3)
= 8 × 2
= 16
问题 2:求解表达式 10 2 – 6 2 。
解决方案:
To solve the expression, first solve the 2nd powers on the numbers and then subtract the second term by the first term. However, the same problem can be solved in an easier way by simply applying a formula, the formula is,
x2 – y2 = (x + y)(x – y)
102 – 62 = (10 + 6)(10 – 6)
= 16 × 4
= 64
问题 3:求解表达式 8 2 + 2 2 。
解决方案:
To solve the expression, first solve the 2nd powers on the numbers and then add the second term by the first term.
82 + 22 = (8 × 8) + (2 × 2)
= 64 + 4
= 68