指数定律是数学中处理指数运算的基本规则。在指数表达式中,底数表示被乘的数,指数表示底数自乘的次数。例如二的三次方,表示二乘以自己三次,等于八。掌握这些定律能帮助我们简化复杂的指数表达式。
乘法定律是指数运算的第一个重要规则。当两个具有相同底数的指数相乘时,结果等于底数的指数相加次方。例如二的三次方乘以二的四次方,等于二的七次方。这是因为我们实际上是将所有的底数因子相乘,总共有七个二相乘。
The multiplication law is the first fundamental rule of exponents. When multiplying two powers with the same base, we simply add their exponents together. For example, two to the third power times two to the fourth power equals two to the seventh power.
The power of a power law states that when we raise a power to another power, we multiply the exponents. For instance, two to the third power, all raised to the fourth power, equals two to the twelfth power. This happens because we're multiplying the base by itself multiple times.
The division law is the second important rule of exponents. When dividing two powers with the same base, the result equals the base raised to the difference of the exponents. For example, two to the seventh power divided by two to the third power equals two to the fourth power. This works because common factors in the numerator and denominator cancel out.
Zero and negative exponents follow special rules. Any non-zero number raised to the power of zero equals one. This comes from the division law when the exponents are equal. Negative exponents represent reciprocals - a number to the negative n power equals one divided by that number to the positive n power.
When powers have different bases but the same exponent, we can combine them in special ways. For multiplication, we can multiply the bases and keep the same exponent. For division, we can divide the bases and keep the same exponent. These rules help simplify complex expressions with multiple terms.
除法定律是指数运算的第二个重要规则。当两个具有相同底数的指数相除时,结果等于底数的指数相减次方。例如二的七次方除以二的三次方,等于二的四次方。这是因为分子分母中的公共因子可以约去。
幂的幂定律说明当一个幂再次被乘方时,我们将指数相乘。例如二的三次方的四次方,等于二的十二次方。这是因为我们实际上是将底数重复相乘多次,总的乘法次数等于两个指数的乘积。