→ nonumber :3. tan用taylor Σ1/3->div. 11/18 12:24
推 alasa15 :2.cos(1/n)-1=cos(1/n)-cos(0)=(1/n)*sin(t),0<t<1/n 11/18 12:28
→ alasa15 :3. lim(n->∞) n^3(tan(1/n)-1/n) ≠ 0 11/18 12:32
推 keith291 :1.用1/n去極限比較檢驗 2.用1/n^2去極限比較檢驗 11/18 12:54
→ keith291 :都是用talyor看出原級數約為怎樣的order再去驗證 11/18 13:00
→ nobrother :謝謝大家 11/18 13:17