Question

If one root of the equation 2x² + kx + 4 = 0 is 2, then the other root is 

A. 6 

B. – 6 

C. – 1 

D. 1

Answer 1

In the given equation 2x² + kx + 4 = 0 

Let α and β be the two roots 

α = 2 (given) 

here a = 2, b = k and c = 4 

sum of the roots

⇒ α + β = \(-b/a\)

⇒ 2 + β = \(-k/2\)

β = – k 

α β = 2 

β = 2/2 = 1(putting value of α = 2)