Practice30 Create account

For $2 x^{2} + k x + 8 = 0$ to have equal roots, the positive value of $k$ is:

Class 10The Quadratic FormulaQuadratic Equations

A9
B8
C7
D16

Step-by-Step Solution

Equal roots:

D = 0 \Rightarrow k^{2} - 4 (2) (8) = 0 \Rightarrow k^{2} = 64 \Rightarrow k

= ±8. Positive value is 8.

Answer: B) 8

Master this chapter in 30 minutes a day.

Don't just memorise the answer — build a daily practice habit.

Practice 5 Similar Questions Free →

All The Quadratic Formula practice questions

More Class 10 The Quadratic Formula practice

A path of uniform width x metres surrounds a rectangular lawn 20 m by 10 m. The total…Two pipes together fill a tank in 6 hours. The larger pipe alone takes 5 hours less than…If one root of x^2 - 8x + k = 0 is 3, find the other root using the formula and the…A motor boat whose speed in still water is 18 km/h takes 1 hour more to go 24 km…For (k+1)x^2 - 6(k+1)x + 3(k+9) = 0 (k not -1) to have equal roots, find the value of k.