1.圖:
http://space.uwants. com/attachments/2007 /08/30/711253_200708 301910462.jpg
If the solid is cut into two identical parts, find the increase in the total surface ara correct to the nearst cm^2
下半 part 係咪半球呀? 係就有得計, 唔係無得計
當係啦
cut into two identical parts, 應該垂直係中間咁 cut 落去
多左既面 係兩塊半圓 with 半徑 4 cm, 兩個三角形, 高 8 cm, 底 8 cm
increase in the total surface ara
= (2) [ (1/2)(pi)(4^2) + (1/2)(8)(8) ]
= 114 cm^2
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2. P(1+6.25%)T=2P 下一步點解唔可以直接除走個P 即: 1.0625T=2 ??
如果 P = 0, 就唔可以咁除
如 P 係非零, 可以兩邊除
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3. 計a^15/ a^6 時因為約簡, 可以除ge 時侯指數相減
但計a^15 / a^ -6 ge 時候, 下一步應a^15+6 而唔應該寫a^15-(-6)??
雖然最後都一樣, 但冇理由a^15-(-6) 因為a^15 / a^ -6等於a^15 x a^6
真係唔知你問乜
點解唔寫得 a^15 / a^ -6 = a^[15-(-6)] = a^(15+6) = a^21
a^15 / a^ -6 = a^15 x a^6 = a^(15+6) = a^21
究竟有乜問題? 唔知點幫你
2007-08-30 21:40:48 補充:
慢左, 不過第二題唔一定可以兩邊除請多多支持