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標題:

數學1999past paper既paper2

發問:

數學1999past paper既paper2第50題答案系乜野呀??? 更新: 要過程... 更新 2: 仲有98年paper2既第17題?

最佳解答:

1999 Paper 2 Q 50 Ans: C (15cm) Join BT. Then ∠BTA = ∠TCB (∠ in alt. segment) Or in other words, ∠BTA = ∠TCA ∠BAT = ∠CAT (Common ∠) So ∠TBA = ∠CTA (The third ∠ of △) Therefore, △ABT～△ATC (A. A. A.) AT/AC = AB/AT (Corr. sides of ～△s) AT/(16+9) = 9/AT AT2 = 25*9 = 225 AT = 15 1998 Paper 2 Q17 Ans: B If x varies inversely as y and directly as z2, then by definition of inverse proportion and direct propotion, xy/z2 is a constant. P.S.: 1. By definition of direct proportion, x is directly proportional to y means x/y is a constant. 2. By definition of inverse proportion, x is inversely proportional to y means xy is a constant. Hope it helps! ^^

其他解答:C8D74AB62542840B