

InterviewSolution
Saved Bookmarks
1. |
Find the values of k for which the quadratic equation \((3k+1)\text{x}^2+2(k+1)\text{x}+1=0\) as equal roots. Also, find these roots. |
Answer» For a quadratic equation, ax2 + bx + c = 0, D = b2 – 4ac If D = 0, roots are equal \((3k+1)\text{x}^2+2(k+1)\text{x}+1=0\) ⇒ D = 4(k + 1)2 – 4(3k + 1) = 0 ⇒ k2 + 2k + 1 – 3k – 1 = 0 ⇒ k(k – 1) = 0 ⇒ k = 0, 1 When k = 0, Eq. – x2 + 2x + 1 = 0 ⇒ (x + 1)2 = 0 ⇒ x = -1 When k = 1, Eq. – 4x2 + 4x + 1 = 0 ⇒ (2x + 1)2 = 0 ⇒ x = -1/2 |
|