If the quadratic equation kx2 + kx + 1 = 0 has real and equal roots, the value of k is :
0
4
0 and 4
0 or 4
18 Likes
Comparing equation kx2 + kx + 1 = 0, with ax2 + bx + c = 0 , we get :
a = k, b = k and c = 1.
Since, quadratic equation has real and equal roots.
∴ D = 0
∴ b2 - 4ac = 0
⇒ k2 - 4 × k × 1 = 0
⇒ k2 - 4k = 0
⇒ k(k - 4) = 0
⇒ k = 0 or k = 4.
Hence, Option 4 is the correct option.
Answered By
11 Likes
If (k + 2)x2 - 2x + 1 = 0 has real roots then greater value of k(∈ Z) is :
1
3
-1
none of these
Find the greatest value of k ∈ N for which the equation x2 - 4x + k = 0 has distinct real roots.
-4
If x2 - 4x = 5, the value of x is :
5
5 or -1
5 and -1
If x2 - 7x = 0, the value of x is :
7
0 and 7
0 or 7