Advertisements
Advertisements
प्रश्न
Find the value (s) of k for which each of the following quadratic equation has equal roots : kx2 – 4x – 5 = 0
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
Solve the following quadratic equation using formula method only
x2 - 4x - 1 = 0
48x² – 13x -1 = 0
Without actually determining the roots comment upon the nature of the roots of each of the following equations:
3x2 + 2x - 1 = 0
If one root of the quadratic equation ax2 + bx + c = 0 is double the other, prove that 2b2 = 9 ac.
If b2 – 4ac > 0 and b2 – 4ac < 0, then write the nature of roots of the quadratic equation for each given case
Which constant must be added and subtracted to solve the quadratic equation `9x^2 + 3/4x - sqrt(2) = 0` by the method of completing the square?
Every quadratic equation has exactly one root.
For the roots of the equation a – bx – x2 = 0; (a > 0, b > 0), which statement is true?
The roots of the quadratic equation px2 – qx + r = 0 are real and equal if ______.
Which of the following equations has imaginary roots?
