Share

Books Shortlist

# In the Following Determine the Set of Values of K for Which the Given Quadratic Equation Has Real Roots: 2x2 + Kx + 2 = 0 - CBSE Class 10 - Mathematics

#### Question

In the following determine the set of values of k for which the given quadratic equation has real roots:

2x2 + kx + 2 = 0

#### Solution

The given quadric equation is 2x2 + kx + 2 = 0, and roots are real.

Then find the value of k.

Here, a = 2, b = k and c = 2

As we know that D = b2 - 4ac

Putting the value of a = 2, b = k and c = 2

= k2 - 4 x (2) x (2)

= k2 - 16

The given equation will have real roots, if D ≥ 0

⇒ k2 - 16 ≥ 0

⇒ k2 ≥ 16

rArrk>=sqrt16Or k <=-sqrt16

⇒ k ≥ 4 Or k ≤ -4

Is there an error in this question or solution?

#### Video TutorialsVIEW ALL [7]

Solution In the Following Determine the Set of Values of K for Which the Given Quadratic Equation Has Real Roots: 2x2 + Kx + 2 = 0 Concept: Nature of Roots.
S