• # question_answer Which of the following line is tangent to the curve, $y={{x}^{2}}-x$ A)  $x-y=0$                     B)  $x+y=0$ C)  $x-y=2$                     D)  $x+y=1$

Given curve, $y={{x}^{2}}-x$ When $x-y=0$ or $y=x$ from Eq. (i) ${{x}^{2}}-2x=0$ its discriminant $D\ne 0$ When $x+y=0$ or $y=-x$ from Eq. (i) ${{x}^{2}}=0$ its discrimanat D = 0 Hence, $x+y=0$ is a tangent.