推 jolin19 : 所以答案是-2pi? 09/17 04:23
※ 引述《jolin19 (alex)》之銘言：
: (1) If F is a force, this give the work done in the displacement along C.
: F = [z,x,y], C:r = [cost,sint,t] from(1,0,0) to (1,0,4pi).
: calculate ∫F(r) ⊙ dr?
: 算出來∫F(r) ⊙ dr = ∫(-tsint+cos^2t+sint)dt
: 請問這個(1,0,0) to (1,0,4pi)積分上下限要怎取?
C的路徑是一個右手螺旋向上
起始點的z = t = 0
=> t_i = 0
走到
起始點的z = t = 4pi
=> t_f = 4pi
所以t的下限是0
上限是4pi
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