Question

If the equation x^2 -bx+1=0 doesn't form real root then prove that -2

Answer 1

Your question is wrong.
it has to be like
"If the equation
${x}^{2} - b \times x + 1 = 0$
doesn't form real root then prove that the value of b € (-2,2).


for non real roots the value of
${b}^{2} - 4 \times a \times c$
less than zero.
a=1
c=1
hence equation becomes
${b}^{2} - 4 < 0$
on solving this enequality we get
b belongs in between (-2,2).