Question

数学集合问题求解

Y=x方+ax+b,A={X\Y=X}={a}.M={(a,b)}求M

Answer 1

y=x^2+ax+b
x=x^2+ax+b ( y=x)
x^2+(a-1)x+b =0
a is solution then
a^2 +(a-1)a +b =0
b =a(1-2a)

M ={ (a,b)}
= { (a,a(1-2a))}