verify Theorem 3.32 by finding the matrix of S T (a) by direct substitution and (b) by matrix multiplication of [S][T]
,*: 4 t' -.vx9+ yv, :t\+ e-+q.\ tf- uq + -,t1Q,rqr\2"rpx (f t'"1x3t9'"1 ,S+ r] - L.4,ti u, # fuA,t /*,r, /"(J,,,{ ,x = 3lj *3 \q'ol Q o)'€J Y /O=Y ,t,;/'z-'r; *\ /t)tr\J- >"( 6- -x+x^d *iv -/ qv ))'( l.\* U\' L_,, Y +.rJ-,''+tUS \7 ,\ n t-|xf* z\ zX --> L'l-x1e'r7 Y 'Y4aWaWr>75 -.Lln\rr+Q