Q91
ArithmeticAlgebra, Equations & Operations
The roots of the quadratic equation $5x^2 + 13x + k = 0$ are reciprocal to each other, then value of $k$ will be
- a.5
- b.0
- c.4
- d.6
Answer: (A) 5
If the roots are reciprocals their product is 1. The product of roots is $\frac{k}{5}$, so $\frac{k}{5} = 1$ and $k = 5$. $k = 0$ would make one root zero, which has no reciprocal.