If one of the zero of the quadratic polynomial f(x) = 4x2 – 8kx –

1.	If one of the zero of the quadratic polynomial f(x) = 4x2 – 8kx – 9 is negative of the other, then find the value of k.
Answer» From the question, it’s given that: The quadratic polynomial f(x) where a = 4, b = -8k and c = – 9 And, for roots to be negative of each other, let the roots be α and – α. Sum of the roots = α – α = \(\frac{-b}{a}\) = – \(\frac{(-8k)}{1}\) = 8k = 0 [∵ α – α = 0] ⇒ k = 0

If one of the zero of the quadratic polynomial f(x) = 4x2 – 8kx – 9 is negative of the other, then find the value of k.

Answer»

From the question, it’s given that:

The quadratic polynomial f(x) where a = 4, b = -8k and c = – 9

And, for roots to be negative of each other, let the roots be α and – α.

Sum of the roots = α – α = \(\frac{-b}{a}\)

= – \(\frac{(-8k)}{1}\)

= 8k = 0 [∵ α – α = 0]

⇒ k = 0