我要提问:  

问题
高一数学作业必修一

计算:
(e^ln3+e^1/2ln4)(e^ln3-e^1/2ln4)
答案
因为 a^b = N 与  b = log(a)N 等价
所以可得 对数恒等式:a^[log(a)N] = N

故 e^(ln3) = 3 , e^(ln4) = 4

 {e^(ln3) + e^[(1/2)ln4]} * {e^(ln3) - e^[(1/2)ln4]}
= [e^(ln3)]² - {e^[(1/2)ln4]}²
= [e^(ln3)]² - e^(ln4)
= 3² - 4
= 5
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