Re: [線代] orthonormal basis

看板Math作者 (彼得)時間15年前 (2011/02/11 20:50), 編輯推噓1(101)
留言2則, 2人參與, 最新討論串2/3 (看更多)
※ 引述《mqazz1 (無法顯示)》之銘言: : let <u,v> be an inner product defined on an n-dimensional real vector space V : let S be an orthonormal basis of V : if [u]_s = (u1, u2, ..., un)^T and [v]_s = (v1, v2, ..., vn)^T : are the coordinates of u and v : prove that <u,v> = u1v1 + u2v2 + ... + unvn : http://ppt.cc/s9~Z <sol> By 題目, Let S={w_1,w_2,..,w_n} is an othonormal basis for V, n n u= Σ(u_i)*(w_i) v=Σ (v_j)*(w_j) i=1 j=1 n n <u,v>= <Σ(u_i)*(w_i) , Σ (v_j)*(w_j)> i=1 j=1 n = Σ (u_i)*(v_j)<w_i,w_j> i=j=1 n = Σ (u_i)(v_i) . i=1 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 220.143.181.86

02/11 22:00, , 1F
請問為什麼 u = Σ(i=1 to n) (u_i)*(w_i) @.@?
02/11 22:00, 1F

02/12 08:42, , 2F
因為題目給的 [u]s is the coordinates of u
02/12 08:42, 2F
文章代碼(AID): #1DLJ2TXw (Math)
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文章代碼(AID): #1DLJ2TXw (Math)