Question

Show that x2 + 4x +5 has no zeroes

Answer 1

         

p(x) = x² + 4x + 5 = 0

a = 1

b = 4

c = 5

b² - 4ac

⇒ 4² - (4 × 1 × 5)

⇒ 16 - 20

⇒ -4

As the discriminant is less than 0,  p(x) has no real zeroes.

Hence proved!

Thank you. :-))