10th Class Mathematics Quadratic Equations Question Bank Quadratic Equation

  • question_answer
    Which of the following quadratic equations have equal roots?

    A)  \[2{{x}^{2}}-3x+5=0\]          

    B)  \[3{{x}^{2}}-4\sqrt{3x}+4=0\]

    C)  \[2{{x}^{2}}-6x+3=0\]

    D)  \[x+\frac{1}{x}=1\]

    Correct Answer: B

    Solution :

    (b): It is easy to mentally solve this problem. Just identify a, b, c in each of the equations. In which ever equation,\[{{b}^{2}}-4ac=0\], it will have equal roots. In (b)\[a=3\,\,\,\,\,b=-4\sqrt{3}\] and \[c=4\] \[\therefore {{b}^{2}}-4ac={{\left( -4\sqrt{3} \right)}^{2}}-4\times 3\times 4=0\]


You need to login to perform this action.
You will be redirected in 3 sec spinner