82幂的乘方和积的乘方 (1)
8.2 幂的乘方和积的乘方 (1)
复回顾 计算 (1)am·an (2)a7a3 (3)10×102×104(4)(m+n)3(m+n)2
计算: (1) a m ·an (2) a 7 ·a3 (3)10×102×104 3 2 (4) (m+ n) (m+ n)
探索计算: (1)(23)5=23·23·23·23·23=23+3+3+3+3 =215=23×5 (2)(a4)3=a4·a4·a4=a44a12=a4×3 (3)(am)5=am·a·am·am·am= amFmtm+mtim=a5m n个am n个m (4)(am")y=mn.mn.…,amn= amtm+…+m=am (a)n=amn(m、n是正整数) 幂的乘方,底数不变,指数相乘
计算: ⑴(23) 5 = 23·23·23·23·23 = 23+3+3+3+3 = 215 ⑵(a4) 3 ⑶(am) 5 =a4·a4·a4 =a4+4+4 =a12 =am·am·am·am·am =am+m+m+m+m =a5m =2 3×5 =a4×3 (4) (a m) n= a m·am· … ·am n个a m = am+m+ … +m n个m = amn (am) n=amn (m、n是正整数) 幂的乘方,底数不变,指数相乘
试 【例1】计算: (1)(104)2(2)(an)4(m为正整数 (3)-(x3)2(4)-(y3)m (5)(xn+1)2 (6)[(xy)2]3 (7)[(am)n]P(8)[(-a3)2]5
【例1】计算: ⑴(104) 2 ⑵ (am) 4 (m为正整数) ⑶ -(x3) 2 ⑷-(y 3)m ⑸ (xn+1) 2 ⑹ [(x-y)2] 3 (7)[(a m ) n ] p (8)[(-a 3) 2] 5
试 例2】计算: (1)x2·(x2)4+(x5)2 (2)(am)2·(a4)m(m是正整数 (3)(m4)2+m5·m3 (4)y·(y4)2-y4yz2·m3
【例2】 计算: (1) x 2·(x2) 4+(x5) 2 (2)(am) 2·(a4) m+1(m是正整数) (3)(m4) 2+m 5·m3 (4)y·(y4) 2-y 4·y2·m3