§3.5
Hoffman 1' Kunze Solutions
p. 10ó ^ 2
Lot B = {oi,q2,q3} 1>c a basis for C3 dcfined by: «i = (1.0. -1), a2 = (1,1,1). and o3 = (2.2.0). Flnd thc dual basis of B.
Lot B* = {if\. </.«• </<} be the dual basis for B and {/j./2,/3} bo the dual basis for tho standard basis. Them g\ = a\J\ + 6j/2 + cj/3. Hence we havo tho following system of equatious:
Tho matrix for tliis system is:
(hM = |
01 - Cl |
= 1 | ||
<jiM = |
fl| +61 +Ci |
= 0 | ||
9i(<*s) = |
2a, +25, |
= 0 | ||
0 -i| i> |
i / |
1 0 |
0 |
1 \ |
1 10 |
0 1 |
0 |
-1 . | |
1 0 1 0, |
1 \ |
0 0 |
1 |
0/ |
A =
Now wo havo g\ - J\ ~ Si-
A similar solution shows g2 = - /2 + /, and </, = -3/1 + fi - 5/3.
P. 105 2:3
If .4 and fi aro n x n matrices ovor tho fiold F. show that traco(.4/?) = traco(/?.4). Now show that similar matricos have the same tracę.
Lot C = AB - (c,>) Tlicn r,j = So c„ = a,kbn. Now:
n n n n
traco(.4£?) = ~Y,Y,bk'a'k = tracc(/i.4).
i-l fc = l fc=l i=l
Now if .4 is similar to B thcn 3 P such that B = P lAP. traoo(P) = tracc(P 1 -4/>) = traco(.4P 1P) — traco(.4).
p. 106 - 4
Lot \* l»c the voctor space of all polynomial functions froin R to R which have <logroo 2 or less: p(x) = c0 + c,x + cjt2. Defino throo linear functionals on V by
f\(p) = ( p(r)d-r, fi(p)= f pix)dr. fsip) = f p(x)<lx.
Jo Jo Jo
Show that {/1./2 /3} is a basis for V* by oxibiting a basis for V of which it is the dual.
Wo wish to hnd a basis B = {/>i./>,./>;$} C V such that {/i./a,/3} = B‘.
{PM = cio + cux + cl2x-p2(i) = C2o + c2i* + c22x2 then we havc:
P.M = c-m+ c3lx + c32x2
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