f.4,,Find the range of values of p.

(1-p)x^2-2(2-p)x+(1-p)=0 has no real roots, find the range of vaules of p.
△<0
[2(2-p)]^2-4(1-p)(1-p)<0
16-16p-4p^2-4+8p-4<0 [(拆( )]
4p^2-12p+8<0 [use quadratic formula]
p=2 or p=1
唔明可再問