初中二次根式 计算题——(“根号2” -1)^2009×(“根号2”+1)^2010的结果是?
问题描述:
初中二次根式 计算题——(“根号2” -1)^2009×(“根号2”+1)^2010的结果是?
答
=(根号2” -1)乘以(根号2” -1)乘以......乘以(“根号2”+1)乘以......
=(“根号2”+1)乘以(“根号2” -1)乘以......(2009个)乘以(“根号2”+1)
根据公式(a+b)乘以(a-b)=a²+b²
=1乘以(“根号2”+1)=“根号2”+1
答
原式=(√2-1)^2009×(√2+1)^2009×(√2+1)
=[(√2-1)×(√2+1)]^2009×(√2+1)
=[(√2)²-1²]^2009×(√2+1)
=1^2009×(√2+1)
=√2+1