Question

if one zero of quadratic polynomial 2x^2-6kx+6x-7 is negative of the other, then k=
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Answer 1

$\huge\underbrace\bold\red{AnSwer :-}$

According to the above solution, k=0.

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Answer 2

Given:

A quadratic polynomial 2x^2-6kx+6x-7 and the one zero of this polynomial is negative of the other.

To find:

The value of k.

Solution:

Let one zero of the given polynomial be m and the other be -m.

As we know that, in a quadratic polynomial ax^2 + bx + c having alpha and beta are the zeroes of this polynomial, the sum of zeroes (alpha and beta) is equal to:

$\frac{ - b}{a}$

where a = coefficient of x^2 and b = coefficient of x.

Hence, using the above, we have

A given polynomial 2x^2-6kx+6x-7 = 2x^2+(-6k+6)x-7 where a = 2 and b = -6k + 6.

Also, m and -m are two zeroes of the given polynomial.

Now,

$m + ( - m) = \frac{ -(- 6k + 6)}{2}$

$\frac{ 6k - 6}{2} = 0$

$6k = 6$

$k = 1$

Hence, k = 1.