Question

21. Show that the equation x2 + ax - 1 = 0 has real and distinct roots for all real values of x.
[Hint : D = (a2 + 4) > 0.]​

Answer 1

Answer:

x^2+ax-1=0

D=b^2-4ac

here; a is 1,b is a, c is -1 then,

a^2-4*1*-1

=a^2+4 is greater than zero

and as we know that when d is greater than zero then roots are real and distinct.