Question

If both the zeroes of the quadratic polynomial is bx^2+bx+c are equal and opposite in sign,then find the value of b.explain

Answer 1

Correct question :

If both the zeroes of the quadratic polynomial is ax^2+bx+c are equal and opposite in sign, then find the value of b. Explain.

Answer :

Value of b is zero.

Explanation:

Correct polynomial :

• ax² + bx + c

Let the zeroes be :

• α and - α

We know that,

Sum of zeroes = -b/a

=> α + ( - α ) = -b/a

=> 0 = -b/a

=> -b = 0 × a

=> b = 0

Hence, value of b is zero.

Answer 2

Solution

Let the given polynomial be p(x) = ax² + bx + c

Given that the zeros of the polynomial are equal and opposite in sign

Let m be one of the zero,then - m would be the other zero

$\rule{300}{2}$

Now,

Sum of Zeros = - x coefficient / x² coefficient

» m + (- m) = - b/a

» 0 = - b/a

» - b = 0

» b = 0

• The value of b is zero

$\rule{300}{2}$

The polynomial would be :

p(x) = ax² + c