Question

if equation ax^2 + 2x + a=0 has two equal and real roots then
a) +-1
b) a=-1,0
c) a=0,1
d) a=0​

Answer 1

∆=b^2-4ac

a=a, b=2, c=a

=2^2-4×a×a

4-4a^2

divide by -1

4a^2-4

(2a+2) (2a-2)

a=1 & a=-1

a=+-1