• # question_answer Assertion (A): If both zeroes of the quadratic polynomial ${{x}^{2}}-2kx+2$are equal in magnitude but opposite in sign then value of k is -. Reason (R): Sum of zeroes of a quadratic polynomial $a{{x}^{2}}+bx+c$ is $\frac{-b}{a}$. A) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A). B) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A). C) Assertion (A) is true but reason (R) is false. D) Assertion (A) is false but reason (R) is true.

 [d] As the polynomial is ${{x}^{2}}-2kx+2$ and its zeroes are equal but opposite sign. Sum of zeroes $=0=\frac{-(-2k)}{1}=0$ $\Rightarrow \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,2k=0\Rightarrow k=0$ So, assertion is incorrect but reason is correct.