精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰ 暑修微積分甲下第二次期中考 課程性質︰ 課程教師︰ 周青松 開課學院: 開課系所︰ 考試日期(年月日)︰2009/9/3 考試時限(分鐘):2小時 是否需發放獎勵金:是 (如未明確表示,則不予發放) 試題 : Make sure to give sufficient reason in each problem or you will NOT get any credit for your answer. A. (a) Set a = a1i + a2j + a3k and b = b1i + b2j + b3k Show that a x b = (a2b3-a3b2)-i(a1b3-a3b1)j+(a1b2-a2b1)k (b) Set a = a1i + a2j + a3k b = b1i + b2j + b3k c = c1i + c2j + c3k | a1 a2 a3 | Show that (a x b) ‧ c = | b1 b2 b3 | | c1 c2 c3 | B. (a)Find f(t) given that f'(t) = 2costi-tsint^2+2tk and f(0)=i+3k (b)Find f(t) given that f'(t) = ti-t(1+t^2)^(-1/2)+te^tk and f(0)=i+2j+3k C. (a) Show that if γ is a differentiable vector function of t ,then the function r = ║γ║ is differentiable at where it is not zero and dγ dr γ‧ ── = r ── dt dt (b) Show that for each integer n and all γ≠0 we have ▽r^n = nr^(n-2)γ D. (xy)^2 Set g(x,y) = ─── if (x,y) ≠ (0,0) x^4+y^4 0 if (x,y) = (0,0) dg dg (a)Show that ─(0,0) and ─(0,0) both exist and evaluate their values dx dy (b)Show that lim g(x,y) doesn't exist (x,y)→(0,0) E. (a) Find all function with gradient yzi + (xz+2yz)j + (xy+y^2)k (b) 2xy Set f(x,y) = ─── if (x,y) ≠ (0,0) x^2+y^2 0 if (x,y) = (0,0) Show that f is not differentiable at (0,0) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.4.94