Re: [中學] 數與式化簡
: 這兩題想不出來，懇請大大們指點感謝!
考慮{a_k}
a_n = √[103 + a_(n-1)]
a_0 = 0, a_k > 0 for k = 1, 2, ...
問n < a_103 < n+1, n = ?
(a_k)^2 - (a_(k-1))^2 = a_(k-1) - a_(k-2)
=> {a_k}為遞增數列
又a_k < √[103 + a_k]
=> a_k有上界[1 + √413]/2 < 11
=> 10 < a_1 < a_103 < 11
=> n = 10
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