If one zero of the polynomial f (x) = 5x2 + 13x + k is reciprocal of t

1.	If one zero of the polynomial f (x) = 5x2 + 13x + k is reciprocal of the , other, then the value of k = ……………B) 5 C) -5 D) - 13/5
Answer» Correct option is (B) 5 Let \(\alpha\;and\;\frac1\alpha\) are zeros of given polynomial f(x). \(\therefore\) Product of zeros \(=\frac{\text{constant term}}{\text{coefficient of }x^2}=\frac k5\) \(\Rightarrow\) \(\alpha.\frac1\alpha\) \(=\frac k5\) \(\Rightarrow\) \(\frac k5=1\) \(\Rightarrow\) k = 5 Correct option is B) 5

If one zero of the polynomial f (x) = 5x2 + 13x + k is reciprocal of the , other, then the value of k = ……………B) 5 C) -5 D) - 13/5

Answer»

Correct option is (B) 5

Let \(\alpha\;and\;\frac1\alpha\) are zeros of given polynomial f(x).

\(\therefore\) Product of zeros \(=\frac{\text{constant term}}{\text{coefficient of }x^2}=\frac k5\)

\(\Rightarrow\) \(\alpha.\frac1\alpha\) \(=\frac k5\)

\(\Rightarrow\) \(\frac k5=1\)

\(\Rightarrow\) k = 5

Correct option is B) 5