(d) Since, we know that if a quadratic equation ax2+bx+c=0 has real roots of equal magnitude and opposite sign. Then, b=0 and product of roots <0 In the given quadratic equation, 3x2−(k2−5k)x+3k2−5k=0 a=3,b=−(k2+5k),c=3k2−5k By Eq. (i), b=0 ⇒−(k2+5k)=0 ⇒k(k+5)=0 ∴k=0,−5 By Eq. (ii), Product of roots <0