Question

If 4x² + x(m + 1) +1 is a perfect square, then a value of m is :

(a) –5

(b) 5

(c) 3

(d) –3

Answer 1

Correct option is (c) 3

4x² + x(m + 1) + 1 is a perfect square of (2x + 1)²

⇒ (2x+ 1)² = 4x² + 4x + 1

then m + 1 = 4

m = 4 − 1 = 3