Question

if the coefficient of x2 and the constant term has opposite signs then the quadratic equation has real roots?​

Answer 1

Answer:

yes .

because :

co-efficient of x^2  mean ( a>0 and c < 0 or a<0 and c >0 )

then by using discriminant  D = b^2 - 4 ac  will return always +ve answer. which  D > 0 for that reason Roots will be real.

Example :  b = either +ve or -ve  => ( b )^2 will return +ve value

and product of +ve and  -ve value will be -ve, so the result of    ( 4*a*c ) be +ve and the sum of two positive value will be                                                   positive .

hope every one got it.