Question

已知函数f(x)= a^x-1/ (a^x) (其中a为大于1的常数),且(a^t)乘f(2t)+m*f(t)≥0对于1

Answer 1

(a^t) * f(2t) + m * f(t) ≥ 0(a^t) * [a^(2t)-1/a^(2t)] + m[a^t-1/ (a^t)] ≥ 0a^(3t)-1/a^t + ma^t -m/a^t ≥ 0a^(3t) + ma^t - (m+1)/a^t ≥ 0∵a＞1,1≤t≤2∴ a^t ＞0∴两边同乘以a^t,不等号不变向a^(4t) ...