+0

# polynomial

0
72
1

If one zero of the polynomial 3x^2 + 12x - k is reciprocal of the other , then find the value of k. ​

Feb 15, 2021

#1
+327
0

If one zero of the quadratic is the reciprocal of the other, then their products of the two zeroes must be equal to 1.

By Vieta's, the product of the two zeroes of a polynomial is equal to the constant term divided by the quadratic term. So:

$$\frac{-k}{3}=1\\ -k=3\\\boxed{k=-3}$$

Feb 15, 2021