Advertisements
Advertisements
प्रश्न
Find the value (s) of k for which each of the following quadratic equation has equal roots : kx2 – 4x – 5 = 0
Advertisements
उत्तर
kx2 – 4x – 5 = 0
Here a = k, b = -4, c = 5
∴ D = b2 - 4ac
= (-4)2 - 4 x k x (-5)
= 16 + 20k
∵ Roots are equal.
∴ D = 0
⇒ b2 - 4ac = 0
∴ 16 + 20k = 0
⇒ 20k = -16
⇒ k = `(-16)/(20)`
= `(-4)/(5)`
Hence k = `(-4)/(5)`.
APPEARS IN
संबंधित प्रश्न
Form the quadratic equation if its roots are –3 and 4.
Find the values of k for which the roots are real and equal in each of the following equation:
4x2 + kx + 9 = 0
In the following determine the set of values of k for which the given quadratic equation has real roots:
3x2 + 2x + k = 0
The equation `3x^2 – 12x + (n – 5) = 0` has equal roots. Find the value of n.
Find the value of the discriminant in the following quadratic equation :
`4 sqrt 3 "x"^2 + 5"x" - 2 sqrt 3 = 0`
If a = 1, b = 8 and c = 15, then find the value of `"b"^2 - 4"ac"`
If a is a root of the equation x2 – (a + b)x + k = 0, find the value of k.
The roots of the quadratic equation 6x2 – x – 2 = 0 are:
State whether the following quadratic equation have two distinct real roots. Justify your answer.
`(x - sqrt(2))^2 - 2(x + 1) = 0`
If one root of the quadratic equation 3x2 – 8x – (2k + 1) = 0 is seven times the other, then find the value of k.
