作者flygey (努力达成目标)
看板trans_math
标题[考古] 请问三题计算题
时间Tue Jul 8 19:14:51 2008
1.Find the critical points and extrema of Z=f(x,y)=xe^xsiny
算的结果
f(x)=sinye^x+sinyxe^x=0
f(y)=xe^xcosy=0
算出(-1,π/2)(-1,-π/2)
这是它的critical point吗 ?
然後再把两点带入f(x,y)求极值
ep
2.Sketch the graph about the polar coordinates r=----------- 0<=θ<=2π
1+ecosθ
and e,p>0 (Hint:discuss the case(i)e=1 (ii)0<e<1 (iii)e>1)
请问这题要从何处开始算
∞
3.Sequence{an} whose the first three term are:
n=1
a1=1+1/2 , a2=1+1/(2+1/2) , a3=1+1/[2+1/(2+1/2)]
(1)what is the fifth term?
(2)Give the general form of an
(3)Is the sequence {an} convergence or divergence ? If convergence then
find it's limit else state the reason for divergence
这题也是不知该用什麽公式算
感谢版友指导解题
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