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发表于 2003-4-24 22:58:00
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Const pi As Double = 3.14159265359
" }" u" @2 q' f: e, DPrivate Function Arccos(x As Double, n As Long) ' n 为函数精度,建议为100
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Case 19 ]/ f( H6 @# M7 j7 X$ \
Arccos = 06 ~2 }+ Q$ Y) g5 d& f
Case -17 c/ E( Q# w/ q2 t2 h
Arccos = pi
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Dim dx As Double, y As Double, i As Long9 A/ D- m% ~/ ]$ Z7 Q' H: S" n
dx = x / n! t3 q- t, g- r4 i1 ]
For i = 1 To n/ G( U# |" U: V/ A, V
y = y + (-1 / Sqr(1 - (dx * i + dx / 2) ^ 2)) * dx; g: ~% S# y; i R( q% m$ L
Next
; K% c; R8 r9 ~" R4 C Arccos = y + pi / 2
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5 g! V5 U+ v# z0 ~( ^ '异常
7 ^. }5 m2 l! N" N/ \2 J6 a2 h End Select
; m6 a7 n. L+ ] \- ]End Function
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0 }" c/ Z# M# a1 {搞定了 |
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