if 1-p is a root of the quadratic equation
x2+px+1−p=0 then its roots are
0, 1
–1, 1
0, – 1
–2, 1
(1−p)2+p(1−p)+(1−p)=0
⇒ (1−p)[1−p+p+1]=0⇒2(1−p)=0⇒ p=1
Thus, equation becomes x2+x=0
x=0 or −1