式3: left parenthesis, 0 , 6 "k" squared minus 4 "k" plus 7 , right parenthesis0,6k2−4k+7
3
式4: left parenthesis, 2 left parenthesis, "k" minus 1 , right parenthesis , 2 "k" squared plus 4 "k" plus 3 , right parenthesis2k−1,2k2+4k+3
4
式5: left parenthesis, "x" minus 2 left parenthesis, "k" minus 1 , right parenthesis , right parenthesis squared plus 2 left parenthesis, "k" plus 1 , right parenthesis squared plus 1x−2k−12+2k+12+1