A={x|x^+px+q=x} B={x|(x-1)^+p(x-1)+q=x-1}若A={2}求集合B
热心网友
x^2+px+q=x == x^2+(p-1)x+q=0有两个相等的实根x=-(p-1)/2=2 == p=-3所以(p-1)^2-4q=0(x-1)^2+p(x-1)+q=x-1 == (x-1)^2+(p-1)(x-1)+q=0== x-1={-(p-1)±√[(p-1)^2-4q]}/2=-(p-1)/2=2∴x=3,即B={3}.
热心网友
解,∵={x|x^+px+q=x}={2}∴x^+px+q=x=2整理得2p+q+2=0代入集合B中,(x-1)^+p(x-1)+q=x-1可以化成:(x-1)^+p(x-1)+q-x+1=0即x^2-3x+p(x-3)=0;再整理成:(x-3)(x+p)=0解得x=3或x=-p集合B={x|x=3或x=-p}