作者JohnMash (Paul)
看板Math
标题Re: [中学] 97嘉中资优班考题
时间Wed Jul 6 19:38:13 2011
※ 引述《qpzmm (钦仔)》之铭言：
: 化简: [4^(1/3)-1]^1/2 + [16^(1/3)-4^(1/3)]^(1/2)
a^3=4 and a>1
a^4=4a
a^2=2√a
K=√(a-1) + √(a^2-a)
=(√a + 1) √(a-1)
K^2 =(√a + 1)^2 (a-1)
=(a+1+2√a)*(a-1)
=(a^2+a+1)(a-1)
=a^3-1=3
K=√3
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1F：→ qpzmm :谢谢! 07/06 22:14