Question

if two roots of quadratic equation ax square + bx + c = 0, a is not equals to zero are equal in magnitude but opposite in sign then find the value of b

Answer 1

Since the roots are equal and opposite in sign so one root will be suppose m and other will be thus -m

Thus sum of roots = 0
So,
-b/a = 0 = sum of roots = - coefficient of x / coefficient of x^2

Hence b = 0

Answer 2

Answer:

Let the two roots be alpha and beta.

Alpha=-beta.

Alpha + beta =-b/a

=-beta+beta = -b/a

= 0 = -b/a

= -b = 0

= b =0.

Feel free to message me if you have any doubts.