arrow
arrow
arrow
If x2−4x+4b=0x^2-4x+4b=0x2−4x+4b=0​has two real solutions, find the value of 'b'.
Question

If x24x+4b=0x^2-4x+4b=0​has two real solutions, find the value of 'b'.

A.

b = 0

B.

b ≥ 1

C.

b = +1, -1

D.

b ≤ 1

Correct option is D

Given:

x2- 4x + 4b = 0 has two real solutions.

Concept Used:

Discriminant for a quadratic equation ax2 + bx + c = 0

b2 - 4ac ≥ 0

​Solution:

The discriminant Δ for this equation is:

Δ=(4)24(1)(4b)Δ=1616b\Delta = (-4)^2 - 4(1)(4b) \\\Delta = 16 - 16b \\​​

For the quadratic equation to have two real solutions, the discriminant should be non-negative:

1616b016 - 16b \geq 0 \\​​

Simplifying this inequality:

16116b11b\frac{16}{1} \geq \frac{16b}{1} \\1 \geq b \\​​

Thus, the value of b must satisfy b1.

Therefore, the correct answer is b1 for the quadratic equation to have two real solutions.

Free Tests

Free
Must Attempt

CBT-1 Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

RRB NTPC Graduate Level PYP (Held on 5 Jun 2025 S1)

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

CBT-1 General Awareness Section Test 1

languageIcon English
  • pdpQsnIcon40 Questions
  • pdpsheetsIcon30 Marks
  • timerIcon25 Mins
languageIcon English
test-prime-package

Access ‘RRB JE CBT-I’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
354k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow